code: function _emitChange(propname/*, arg1, ..., argX*/) {
          var args = arguments
          var kp = $normalize($join(_rootPath(), propname))
          args[0] = CHANGE_EVENT + ':' + kp
          _emitter.emit(CHANGE_EVENT, kp)
          emitter.emit.apply(emitter, args)
  
          args = $util.copyArray(args)
          args[0] = kp
          args.unshift('*')
          emitter.emit.apply(emitter, args)
      }
docs: local proxy for EventEmitter