docs: def get_count(self, key, column_parent, predicate, consistency_level):
      """
      returns the number of columns matching <code>predicate</code> for a particular <code>key</code>,
      <code>ColumnFamily</code> and optionally <code>SuperColumn</code>.
  
      Parameters:
       - key
       - column_parent
       - predicate
       - consistency_level
      """
      self._seqid += 1
      d = self._reqs[self._seqid] = defer.Deferred()
      self.send_get_count(key, column_parent, predicate, consistency_level)
      return d