code: def matches_query(self, key, query):
          
          dumped = query.dump()
          dumped['className'] = query._query_class._class_name
          self._add_condition(key, '$inQuery', dumped)
          return self
docs: 增加查询条件，限制查询结果对象指定字段的值，与另外一个查询对象的返回结果相同。
  
          :param key: 查询条件字段名
          :param query: 查询对象
          :type query: Query
          :rtype: Query