Directive block - Gen<None> - 24 - (0:0,0)
    Transition span - Gen<None> - [@] - SpanEditHandler;Accepts:None - (0:0,0) - Tokens:1
        CSharpTokenType.Transition;[@];
    MetaCode span - Gen<None> - [tagHelperPrefix] - SpanEditHandler;Accepts:None - (1:0,1) - Tokens:1
        CSharpTokenType.Identifier;[tagHelperPrefix];
    Markup span - Gen<None> - [ ] - SpanEditHandler;Accepts:None - (16:0,16) - Tokens:1
        CSharpTokenType.WhiteSpace;[ ];
    Code span - Gen<TagHelperPrefix:{Foo   ";Foo   "} [RZ1000(23:0,23 [1] ), RZ1019(17:0,17 [7] ), RZ1020(17:0,17 [7] )]> - [Foo   "] - SpanEditHandler;Accepts:AnyExceptNewline - (17:0,17) - Tokens:3
        CSharpTokenType.Identifier;[Foo];
        CSharpTokenType.WhiteSpace;[   ];
        CSharpTokenType.StringLiteral;["];RZ1000(23:0,23 [1] )
