Directive block - Gen<None> - 9 - (0:0,0)
    Code span - Gen<Import: Foo;> - [using Foo] - SpanEditHandler;Accepts:AnyExceptNewline - (0:0,0) - Tokens:3
        CSharpTokenType.Keyword;[using];
        CSharpTokenType.WhiteSpace;[ ];
        CSharpTokenType.Identifier;[Foo];
