code: def contains(self, data):
          
          bfo = BitFieldOperation(self.database, self.key)
          for bit_index in self._get_seeds(data):
              bfo.get('u1', bit_index)
          return all(bfo.execute())
docs: Check if an item has been added to the bloomfilter.
  
          :param bytes data: a bytestring representing the item to check.
          :returns: a boolean indicating whether or not the item is present in
              the bloomfilter. False-positives are possible, but a negative
              return value is definitive.