def connect(self): 
        try:
            self.connection = pymongo.Connection(self.host, self.port)
            self.db = self.connection[self.name]
        except AutoReconnect:
            raise DatabaseException("It's not possible connect to the database")
def add_item(self, item_value=None, index=None):
    if item_value is None:
      item_value = self._new_item_default_value