anchor.diff:        push(forest.block(
             token,
             <Statement>[
  -            deprecated_buildCompileTimeErrorStatement(
  -                "Expected '{'.", token.charOffset)
  +            deprecated_buildCompileTimeErrorStatement(null, token.charOffset,
  +                fasta.templateExpectedFunctionBody.withArguments(token))
             ],
             null));
       }
  
positive.code: 
    @override
    Expression deprecated_buildCompileTimeError(String error,
        [int charOffset = -1]) {
      return new SyntheticExpressionJudgment(buildCompileTimeError(
          fasta.templateUnspecified.withArguments(error), charOffset, noLength));
    }
  
    @override
  
negative.code:   }
  
    Statement deprecated_buildCompileTimeErrorStatement(error,
        [int charOffset = -1, fasta.Message message]) {
      return new ExpressionStatementJudgment(
          deprecated_buildCompileTimeError(error, charOffset, message), null);
    }
  
    Statement buildCompileTimeErrorStatement(Message message, int charOffset,
  