anchor.diff:        )
       ;
   
  -methodParameters
  -    : typeParameters? parameters+ 
  -      //metatypes? 
  -      typeConstraints?
  -    ;
       
   block returns [Block block]
       : LBRACE 
  
positive.code:     //-> ^(OBJECT_DEFINITION VALUE_MODIFIER memberName extendedType? satisfiedTypes? classBody?) 
      ;
  
  voidMethodDeclaration
      : VOID_MODIFIER memberName methodParameters?
        ( 
          block 
        //-> ^(METHOD_DEFINITION VOID_MODIFIER memberName methodParameters? block)   
        | specifier?
          SEMICOLON
        //-> ^(METHOD_DECLARATION VOID_MODIFIER memberName methodParameters? specifier?)   
        )
      ;
  
negative.code:       )
      /*| unionType memberName
        ( 
          typeParameters? 
          parameters+
          //metatypes? 
          typeConstraints?
          ( 
            memberBody[$unionType.tree] 
          //-> ^(METHOD_DEFINITION unionType memberName methodParameters memberBody)
  