anchor.diff:      CHAR_CST;
       CLASS_BODY;
       CLASS_DECL;
  +    OBJECT_DECL;
  +    CASE_DECL;
       CONDITION;
       DO_BLOCK;
       DO_ITERATOR;
  
positive.code:     :   'extends'
      ;
  
  FINALLY
      :   'finally'
      ;
  
negative.code:     -> ^(INTERFACE_DECL interfaceDeclaration)
      | aliasDeclaration
      -> ^(ALIAS_DECL aliasDeclaration)
      | objectDeclaration
      -> ^(OBJECT_DECL objectDeclaration)
      ;
  
  enumeratedTypeDeclaration
      : classDeclaration
      -> ^(CLASS_DECL classDeclaration)
      | objectDeclaration
      -> ^(OBJECT_DECL objectDeclaration)
      | caseDeclaration
      -> ^(CASE_DECL caseDeclaration)
      ;
  
  /*toplevelExpression
  