Directive block - Gen<Directive:{custom;SingleLine;Unrestricted}> - 29 - (0:0,0)
    Transition span - Gen<None> - [@] - SpanEditHandler;Accepts:None - (0:0,0) - Symbols:1
        CSharpSymbolType.Transition;[@];
    MetaCode span - Gen<None> - [custom] - SpanEditHandler;Accepts:None - (1:0,1) - Symbols:1
        CSharpSymbolType.Identifier;[custom];
    Code span - Gen<None> - [ ] - SpanEditHandler;Accepts:WhiteSpace - (7:0,7) - Symbols:1
        CSharpSymbolType.WhiteSpace;[ ];
    Code span - Gen<DirectiveToken {;Namespace;Opt:False}> - [BaseNamespace.Foo.Bar] - DirectiveTokenEditHandler;Accepts:NonWhiteSpace - (8:0,8) - Symbols:5
        CSharpSymbolType.Identifier;[BaseNamespace];
        CSharpSymbolType.Dot;[.];
        CSharpSymbolType.Identifier;[Foo];
        CSharpSymbolType.Dot;[.];
        CSharpSymbolType.Identifier;[Bar];
