anchor.diff:  
   primary
       :   literal
  -    |   Identifier
       ;
   
   literal
  
positive.code:     ;
  
  fieldDeclaration
      :   accessType type variableDeclarators delimiter
      ;
  
  variableDeclarators
  
negative.code: 
  LINE_COMMENT
      :   '//' ~[\r\n]* -> skip
      ;
  	
  WS: [ \n\t\r]+ -> skip;