anchor.diff:      ;
   
   apiElementValuePairs
  -    :  tags? ','  descripton? ',' producer
  +    :  (tags ',')?  (descripton ',')? producer
       ;
   
   protoclo
  
positive.code:     ;
  
  antApiResponses
      :   '@' 'ApiResponses' ( '(' ( elementValuePairs | elementValue )? ')' )?
      ;
  
  elementValuePairs
  
negative.code: 
  expression
      :   primary
  //    |  'new' Identifier '(' methodParams? ')'
      |  Identifier '.' Identifier '(' methodParams? ')'
      |  Identifier '(' methodParams? ')'
      |  'new' classType '(' methodParams? ')'
  //    |   expression ('++' | '--')
  //    |   ('+'|'-'|'++'|'--') expression
  //    |   ('~'|'!') expression
  