public Property Valid_token_sequence_lexes_back_to_itself()
 {
     return(Prop.ForAll(Arbitrary.PsuedoTokenList(), tokens =>
     {
         var input = string.Concat(tokens.Select(t => t.Text));
         var result = Lex(input);
         var outputAsPsuedoTokens = result.ToPsuedoTokens();
         var expectedPsuedoTokens = tokens.Append(PsuedoToken.EndOfFile()).ToFixedList();
         return expectedPsuedoTokens.SequenceEqual(outputAsPsuedoTokens)
         .Label($"Text: „{input.Escape()}„")
         .Label($"Actual:   {outputAsPsuedoTokens.DebugFormat()}")
         .Label($"Expected: {expectedPsuedoTokens.DebugFormat()}");
     }));
 }