anchor.diff:  
   const ParserErrorCode _FIELD_INITIALIZED_OUTSIDE_DECLARING_CLASS =
       const ParserErrorCode('FIELD_INITIALIZED_OUTSIDE_DECLARING_CLASS',
  -        r"A field can only be initialized in it's declaring class",
  +        r"A field can only be initialized in its declaring class",
           correction:
               "Try passing a value into the superclass constructor, or moving the initialization into the constructor body.");
   
  
positive.code: 
  const ParserErrorCode _MISSING_ASSIGNABLE_SELECTOR = const ParserErrorCode(
      'MISSING_ASSIGNABLE_SELECTOR',
      r"Missing selector such as '.<identifier>' or '[0]'.",
      correction: "Try adding a selector.");
  
  const ParserErrorCode _MISSING_ASSIGNMENT_IN_INITIALIZER =
  
negative.code: 
  const ParserErrorCode _EQUALITY_CANNOT_BE_EQUALITY_OPERAND = const ParserErrorCode(
      'EQUALITY_CANNOT_BE_EQUALITY_OPERAND',
      r"A comparison expression can't be an operand of another comparison expression.",
      correction: "Try putting parentheses around one of the comparisons.");
  
  const ParserErrorCode _EXPECTED_BODY = const ParserErrorCode(
      'EXPECTED_BODY', r"A #string must have a body, even if it is empty.",
  