anchor.diff:  const ParserErrorCode _MISSING_PREFIX_IN_DEFERRED_IMPORT =
       const ParserErrorCode('MISSING_PREFIX_IN_DEFERRED_IMPORT',
           r"Deferred imports should have a prefix.",
  -        correction: "Try adding a prefix to the import.");
  +        correction:
  +            "Try adding a prefix to the import by adding an 'as' clause.");
   
   const ParserErrorCode _MISSING_STATEMENT =
       const ParserErrorCode('MISSING_STATEMENT', r"Expected a statement.");
  
positive.code: 
  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",
          correction:
              "Try passing a value into the superclass constructor, or moving the initialization into the constructor body.");
  
  
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.",
  