code: def increment_client_count(self, ofs = 1):
          
          self._uc += ofs
          assert self._uc > -1, "Increments must match decrements, usage counter negative: %i" % self._uc
  
          if self.client_count() == 0:
              self.release()
              return True
          else:
              return False
docs: Adjust the usage count by the given positive or negative offset.
          If usage count equals 0, we will auto-release our resources
          :return: True if we released resources, False otherwise. In the latter case, we can still be used