anchor.diff:  classDeclaration
   @init {	
     ClassDefinition classDef = new ClassDefinition();
  -	$SourceFile::file.classDef_$eq(classDef);
  +	$SourceFile::file.classDef_\$eq(classDef);
   	paraphrases.push("in class definition");
   }
   @after {
  
positive.code: 	  if ($exp != null) {
    	  for (Object item : $exp) {
  	      Expression expression = ((expression_return)item).exp;
  	      $args.$plus$eq(expression);
  	    }
  	  }
  	}
  
negative.code: 	
  modifier [Buffer<Enumeration.Value> mods]
  	: m=('mutable' | 'delegate' | 'native')
  	{ mods.\$plus\$eq(Modifier.valueOf($m.text).get()); }
  	;
  
  classBlock
  