diff --git a/src/Microsoft.AspNetCore.Identity/RoleManager.cs b/src/Microsoft.AspNetCore.Identity/RoleManager.cs
index 8dd42b45a3..e7c30ce0c9 100644
--- a/src/Microsoft.AspNetCore.Identity/RoleManager.cs
+++ b/src/Microsoft.AspNetCore.Identity/RoleManager.cs
@@ -158,7 +158,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (role == null)
             {
-                throw new ArgumentNullException("role");
+                throw new ArgumentNullException(nameof(role));
             }
             var result = await ValidateRoleInternal(role);
             if (!result.Succeeded)
@@ -195,7 +195,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (role == null)
             {
-                throw new ArgumentNullException("role");
+                throw new ArgumentNullException(nameof(role));
             }
 
             return UpdateRoleAsync(role);
@@ -213,7 +213,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (role == null)
             {
-                throw new ArgumentNullException("role");
+                throw new ArgumentNullException(nameof(role));
             }
 
             return Store.DeleteAsync(role, CancellationToken);
@@ -231,7 +231,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (roleName == null)
             {
-                throw new ArgumentNullException("roleName");
+                throw new ArgumentNullException(nameof(roleName));
             }
 
             return await FindByNameAsync(NormalizeKey(roleName)) != null;
@@ -320,7 +320,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (roleName == null)
             {
-                throw new ArgumentNullException("roleName");
+                throw new ArgumentNullException(nameof(roleName));
             }
 
             return Store.FindByNameAsync(NormalizeKey(roleName), CancellationToken);
@@ -341,11 +341,11 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (claim == null)
             {
-                throw new ArgumentNullException("claim");
+                throw new ArgumentNullException(nameof(claim));
             }
             if (role == null)
             {
-                throw new ArgumentNullException("role");
+                throw new ArgumentNullException(nameof(role));
             }
 
             await claimStore.AddClaimAsync(role, claim, CancellationToken);
@@ -367,7 +367,7 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (role == null)
             {
-                throw new ArgumentNullException("role");
+                throw new ArgumentNullException(nameof(role));
             }
 
             await claimStore.RemoveClaimAsync(role, claim, CancellationToken);
@@ -388,7 +388,7 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (role == null)
             {
-                throw new ArgumentNullException("role");
+                throw new ArgumentNullException(nameof(role));
             }
             return claimStore.GetClaimsAsync(role, CancellationToken);
         }
diff --git a/src/Microsoft.AspNetCore.Identity/UserManager.cs b/src/Microsoft.AspNetCore.Identity/UserManager.cs
index bc561f5a5d..1a0635177a 100644
--- a/src/Microsoft.AspNetCore.Identity/UserManager.cs
+++ b/src/Microsoft.AspNetCore.Identity/UserManager.cs
@@ -258,11 +258,11 @@ namespace Microsoft.AspNetCore.Identity
         }
 
         /// <summary>
-        /// Gets a flag indicating whether the backing user store supports returning 
+        /// Gets a flag indicating whether the backing user store supports returning
         /// <see cref="IQueryable"/> collections of information.
         /// </summary>
         /// <value>
-        /// true if the backing user store supports returning <see cref="IQueryable"/> collections of 
+        /// true if the backing user store supports returning <see cref="IQueryable"/> collections of
         /// information, otherwise false.
         /// </value>
         public virtual bool SupportsQueryableUsers
@@ -353,7 +353,7 @@ namespace Microsoft.AspNetCore.Identity
         }
 
         /// <summary>
-        /// Creates the specified <paramref name="user"/> in the backing store with no password, 
+        /// Creates the specified <paramref name="user"/> in the backing store with no password,
         /// as an asynchronous operation.
         /// </summary>
         /// <param name="user">The user to create.</param>
@@ -393,7 +393,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             return UpdateUserAsync(user);
@@ -412,7 +412,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             return Store.DeleteAsync(user, CancellationToken);
@@ -443,14 +443,14 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (userName == null)
             {
-                throw new ArgumentNullException("userName");
+                throw new ArgumentNullException(nameof(userName));
             }
             userName = NormalizeKey(userName);
             return Store.FindByNameAsync(userName, CancellationToken);
         }
 
         /// <summary>
-        /// Creates the specified <paramref name="user"/> in the backing store with given password, 
+        /// Creates the specified <paramref name="user"/> in the backing store with given password,
         /// as an asynchronous operation.
         /// </summary>
         /// <param name="user">The user to create.</param>
@@ -465,11 +465,11 @@ namespace Microsoft.AspNetCore.Identity
             var passwordStore = GetPasswordStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (password == null)
             {
-                throw new ArgumentNullException("password");
+                throw new ArgumentNullException(nameof(password));
             }
             var result = await UpdatePasswordHash(passwordStore, user, password);
             if (!result.Succeeded)
@@ -510,7 +510,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await Store.GetUserNameAsync(user, CancellationToken);
         }
@@ -526,7 +526,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await Store.SetUserNameAsync(user, userName, CancellationToken);
@@ -546,7 +546,7 @@ namespace Microsoft.AspNetCore.Identity
         }
 
         /// <summary>
-        /// Returns a flag indicating whether the given <paramref name="password"/> is valid for the 
+        /// Returns a flag indicating whether the given <paramref name="password"/> is valid for the
         /// specified <paramref name="user"/>.
         /// </summary>
         /// <param name="user">The user whose password should be validated.</param>
@@ -592,7 +592,7 @@ namespace Microsoft.AspNetCore.Identity
             var passwordStore = GetPasswordStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             return passwordStore.HasPasswordAsync(user, CancellationToken);
@@ -614,7 +614,7 @@ namespace Microsoft.AspNetCore.Identity
             var passwordStore = GetPasswordStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             var hash = await passwordStore.GetPasswordHashAsync(user, CancellationToken);
@@ -648,7 +648,7 @@ namespace Microsoft.AspNetCore.Identity
             var passwordStore = GetPasswordStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
 
@@ -681,7 +681,7 @@ namespace Microsoft.AspNetCore.Identity
             var passwordStore = GetPasswordStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await UpdatePasswordHash(passwordStore, user, null, validatePassword: false);
@@ -719,7 +719,7 @@ namespace Microsoft.AspNetCore.Identity
             var securityStore = GetSecurityStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await securityStore.GetSecurityStampAsync(user, CancellationToken);
         }
@@ -741,7 +741,7 @@ namespace Microsoft.AspNetCore.Identity
             GetSecurityStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await UpdateSecurityStampInternal(user);
@@ -750,10 +750,10 @@ namespace Microsoft.AspNetCore.Identity
 
         /// <summary>
         /// Generates a password reset token for the specified <paramref name="user"/>, using
-        /// the configured password reset token provider. 
+        /// the configured password reset token provider.
         /// </summary>
         /// <param name="user">The user to generate a password reset token for.</param>
-        /// <returns>The <see cref="Task"/> that represents the asynchronous operation, 
+        /// <returns>The <see cref="Task"/> that represents the asynchronous operation,
         /// containing a password reset token for the specified <paramref name="user"/>.</returns>
         public virtual Task<string> GeneratePasswordResetTokenAsync(TUser user)
         {
@@ -777,7 +777,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             // Make sure the token is valid and the stamp matches
@@ -808,11 +808,11 @@ namespace Microsoft.AspNetCore.Identity
             var loginStore = GetLoginStore();
             if (loginProvider == null)
             {
-                throw new ArgumentNullException("loginProvider");
+                throw new ArgumentNullException(nameof(loginProvider));
             }
             if (providerKey == null)
             {
-                throw new ArgumentNullException("providerKey");
+                throw new ArgumentNullException(nameof(providerKey));
             }
             return loginStore.FindByLoginAsync(loginProvider, providerKey, CancellationToken);
         }
@@ -834,15 +834,15 @@ namespace Microsoft.AspNetCore.Identity
             var loginStore = GetLoginStore();
             if (loginProvider == null)
             {
-                throw new ArgumentNullException("loginProvider");
+                throw new ArgumentNullException(nameof(loginProvider));
             }
             if (providerKey == null)
             {
-                throw new ArgumentNullException("providerKey");
+                throw new ArgumentNullException(nameof(providerKey));
             }
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await loginStore.RemoveLoginAsync(user, loginProvider, providerKey, CancellationToken);
@@ -865,11 +865,11 @@ namespace Microsoft.AspNetCore.Identity
             var loginStore = GetLoginStore();
             if (login == null)
             {
-                throw new ArgumentNullException("login");
+                throw new ArgumentNullException(nameof(login));
             }
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             var existingUser = await FindByLoginAsync(login.LoginProvider, login.ProviderKey);
@@ -895,7 +895,7 @@ namespace Microsoft.AspNetCore.Identity
             var loginStore = GetLoginStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await loginStore.GetLoginsAsync(user, CancellationToken);
         }
@@ -915,11 +915,11 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (claim == null)
             {
-                throw new ArgumentNullException("claim");
+                throw new ArgumentNullException(nameof(claim));
             }
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return AddClaimsAsync(user, new Claim[] { claim });
         }
@@ -939,11 +939,11 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (claims == null)
             {
-                throw new ArgumentNullException("claims");
+                throw new ArgumentNullException(nameof(claims));
             }
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await claimStore.AddClaimsAsync(user, claims, CancellationToken);
@@ -966,15 +966,15 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (claim == null)
             {
-                throw new ArgumentNullException("claim");
+                throw new ArgumentNullException(nameof(claim));
             }
             if (newClaim == null)
             {
-                throw new ArgumentNullException("newClaim");
+                throw new ArgumentNullException(nameof(newClaim));
             }
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await claimStore.ReplaceClaimAsync(user, claim, newClaim, CancellationToken);
@@ -996,11 +996,11 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (claim == null)
             {
-                throw new ArgumentNullException("claim");
+                throw new ArgumentNullException(nameof(claim));
             }
             return RemoveClaimsAsync(user, new Claim[] { claim });
         }
@@ -1020,11 +1020,11 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (claims == null)
             {
-                throw new ArgumentNullException("claims");
+                throw new ArgumentNullException(nameof(claims));
             }
 
             await claimStore.RemoveClaimsAsync(user, claims, CancellationToken);
@@ -1044,7 +1044,7 @@ namespace Microsoft.AspNetCore.Identity
             var claimStore = GetClaimStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await claimStore.GetClaimsAsync(user, CancellationToken);
         }
@@ -1064,7 +1064,7 @@ namespace Microsoft.AspNetCore.Identity
             var userRoleStore = GetUserRoleStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             var normalizedRole = NormalizeKey(role);
@@ -1091,11 +1091,11 @@ namespace Microsoft.AspNetCore.Identity
             var userRoleStore = GetUserRoleStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (roles == null)
             {
-                throw new ArgumentNullException("roles");
+                throw new ArgumentNullException(nameof(roles));
             }
 
             foreach (var role in roles.Distinct())
@@ -1125,7 +1125,7 @@ namespace Microsoft.AspNetCore.Identity
             var userRoleStore = GetUserRoleStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             var normalizedRole = NormalizeKey(role);
@@ -1164,11 +1164,11 @@ namespace Microsoft.AspNetCore.Identity
             var userRoleStore = GetUserRoleStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (roles == null)
             {
-                throw new ArgumentNullException("roles");
+                throw new ArgumentNullException(nameof(roles));
             }
 
             foreach (var role in roles)
@@ -1194,7 +1194,7 @@ namespace Microsoft.AspNetCore.Identity
             var userRoleStore = GetUserRoleStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await userRoleStore.GetRolesAsync(user, CancellationToken);
         }
@@ -1214,7 +1214,7 @@ namespace Microsoft.AspNetCore.Identity
             var userRoleStore = GetUserRoleStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await userRoleStore.IsInRoleAsync(user, NormalizeKey(role), CancellationToken);
         }
@@ -1230,7 +1230,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetEmailStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await store.GetEmailAsync(user, CancellationToken);
         }
@@ -1250,7 +1250,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetEmailStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await store.SetEmailAsync(user, email, CancellationToken);
@@ -1272,7 +1272,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetEmailStore();
             if (email == null)
             {
-                throw new ArgumentNullException("email");
+                throw new ArgumentNullException(nameof(email));
             }
             return store.FindByEmailAsync(NormalizeKey(email), CancellationToken);
         }
@@ -1320,7 +1320,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetEmailStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             if (!await VerifyUserTokenAsync(user, Options.Tokens.EmailConfirmationTokenProvider, ConfirmEmailTokenPurpose, token))
@@ -1346,7 +1346,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetEmailStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await store.GetEmailConfirmedAsync(user, CancellationToken);
         }
@@ -1380,7 +1380,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             // Make sure the token is valid and the stamp matches
@@ -1406,7 +1406,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetPhoneNumberStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await store.GetPhoneNumberAsync(user, CancellationToken);
         }
@@ -1426,7 +1426,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetPhoneNumberStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await store.SetPhoneNumberAsync(user, phoneNumber, CancellationToken);
@@ -1436,7 +1436,7 @@ namespace Microsoft.AspNetCore.Identity
         }
 
         /// <summary>
-        /// Sets the phone number for the specified <paramref name="user"/> if the specified 
+        /// Sets the phone number for the specified <paramref name="user"/> if the specified
         /// change <paramref name="token"/> is valid.
         /// </summary>
         /// <param name="user">The user whose phone number to set.</param>
@@ -1452,7 +1452,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetPhoneNumberStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             if (!await VerifyChangePhoneNumberTokenAsync(user, token, phoneNumber))
@@ -1480,7 +1480,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetPhoneNumberStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return store.GetPhoneNumberConfirmedAsync(user, CancellationToken);
         }
@@ -1546,7 +1546,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (tokenProvider == null)
             {
@@ -1582,7 +1582,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (tokenProvider == null)
             {
@@ -1606,13 +1606,13 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (provider == null)
             {
-                throw new ArgumentNullException("provider");
+                throw new ArgumentNullException(nameof(provider));
             }
             _tokenProviders[providerName] = provider;
         }
 
         /// <summary>
-        /// Gets a list of valid two factor token providers for the specified <paramref name="user"/>, 
+        /// Gets a list of valid two factor token providers for the specified <paramref name="user"/>,
         /// as an asynchronous operation.
         /// </summary>
         /// <param name="user">The user the whose two factor authentication providers will be returned.</param>
@@ -1625,7 +1625,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             var results = new List<string>();
             foreach (var f in _tokenProviders)
@@ -1653,7 +1653,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (!_tokenProviders.ContainsKey(tokenProvider))
             {
@@ -1684,7 +1684,7 @@ namespace Microsoft.AspNetCore.Identity
             ThrowIfDisposed();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (!_tokenProviders.ContainsKey(tokenProvider))
             {
@@ -1701,7 +1701,7 @@ namespace Microsoft.AspNetCore.Identity
         /// </summary>
         /// <param name="user">The user whose two factor authentication enabled status should be retrieved.</param>
         /// <returns>
-        /// The <see cref="Task"/> that represents the asynchronous operation, true if the specified <paramref name="user "/> 
+        /// The <see cref="Task"/> that represents the asynchronous operation, true if the specified <paramref name="user "/>
         /// has two factor authentication enabled, otherwise false.
         /// </returns>
         public virtual async Task<bool> GetTwoFactorEnabledAsync(TUser user)
@@ -1710,7 +1710,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserTwoFactorStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await store.GetTwoFactorEnabledAsync(user, CancellationToken);
         }
@@ -1730,7 +1730,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserTwoFactorStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await store.SetTwoFactorEnabledAsync(user, enabled, CancellationToken);
@@ -1744,7 +1744,7 @@ namespace Microsoft.AspNetCore.Identity
         /// </summary>
         /// <param name="user">The user whose locked out status should be retrieved.</param>
         /// <returns>
-        /// The <see cref="Task"/> that represents the asynchronous operation, true if the specified <paramref name="user "/> 
+        /// The <see cref="Task"/> that represents the asynchronous operation, true if the specified <paramref name="user "/>
         /// is locked out, otherwise false.
         /// </returns>
         public virtual async Task<bool> IsLockedOutAsync(TUser user)
@@ -1753,7 +1753,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             if (!await store.GetLockoutEnabledAsync(user, CancellationToken))
             {
@@ -1778,7 +1778,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             await store.SetLockoutEnabledAsync(user, enabled, CancellationToken);
@@ -1798,7 +1798,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await store.GetLockoutEnabledAsync(user, CancellationToken);
         }
@@ -1817,7 +1817,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await store.GetLockoutEndDateAsync(user, CancellationToken);
         }
@@ -1834,7 +1834,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             if (!await store.GetLockoutEnabledAsync(user, CancellationToken))
@@ -1847,8 +1847,8 @@ namespace Microsoft.AspNetCore.Identity
         }
 
         /// <summary>
-        /// Increments the access failed count for the user as an asynchronous operation. 
-        /// If the failed access account is greater than or equal to the configured maximum number of attempts, 
+        /// Increments the access failed count for the user as an asynchronous operation.
+        /// If the failed access account is greater than or equal to the configured maximum number of attempts,
         /// the user will be locked out for the configured lockout time span.
         /// </summary>
         /// <param name="user">The user whose failed access count to increment.</param>
@@ -1859,7 +1859,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             // If this puts the user over the threshold for lockout, lock them out and reset the access failed count
@@ -1886,7 +1886,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
 
             if (await GetAccessFailedCountAsync(user) == 0)
@@ -1898,7 +1898,7 @@ namespace Microsoft.AspNetCore.Identity
         }
 
         /// <summary>
-        /// Retrieves the current number of failed accesses for the given <paramref name="user"/>. 
+        /// Retrieves the current number of failed accesses for the given <paramref name="user"/>.
         /// </summary>
         /// <param name="user">The user whose access failed count should be retrieved for.</param>
         /// <returns>The <see cref="Task"/> that contains the result the asynchronous operation, the current failed access count
@@ -1909,7 +1909,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserLockoutStore();
             if (user == null)
             {
-                throw new ArgumentNullException("user");
+                throw new ArgumentNullException(nameof(user));
             }
             return await store.GetAccessFailedCountAsync(user, CancellationToken);
         }
@@ -1928,7 +1928,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetClaimStore();
             if (claim == null)
             {
-                throw new ArgumentNullException("claim");
+                throw new ArgumentNullException(nameof(claim));
             }
             return store.GetUsersForClaimAsync(claim, CancellationToken);
         }
@@ -1947,7 +1947,7 @@ namespace Microsoft.AspNetCore.Identity
             var store = GetUserRoleStore();
             if (roleName == null)
             {
-                throw new ArgumentNullException("role");
+                throw new ArgumentNullException(nameof(roleName));
             }
 
             return store.GetUsersInRoleAsync(NormalizeKey(roleName), CancellationToken);