anchor.diff:  
   */
   
  -
  -
   grammar GraphQl;
   
   document
  
positive.code: directive
      :   '@' NAME ':' valueOrVariable
      |   '@' NAME
      ;
  
  typeCondition
  
negative.code: selectionSet
      :   '{' selection (','? selection)* '}'
      ;
  
  operationType
      :   'query'
  