anchor.diff:  
   fragment
   Digits
  -    :   Digit (DigitsAndUnderscores? Digit)?
  +    :   Digit (DigitOrUnderscore* Digit)?
       ;
   
   fragment
  
positive.code:     |   'for' '(' forControl ')' statement
      |   'while' parExpression statement
      |   'do' statement 'while' parExpression ';'
      |   'try' block (catches finallyBlock? | finallyBlock)
      |   'try' resourceSpecification block catches? finallyBlock?
      |   'switch' parExpression '{' switchBlockStatementGroup* switchLabel* '}'
      |   'synchronized' parExpression block
      |   'return' expression? ';'
  
negative.code:     |   ';'
      |   statementExpression ';'
      |   Identifier ':' statement
      ;
  
  catchClause
  