code: def to_pb(self):
          
          if self.gc_rule is None:
              return table_v2_pb2.ColumnFamily()
          else:
              return table_v2_pb2.ColumnFamily(gc_rule=self.gc_rule.to_pb())
docs: Converts the column family to a protobuf.
  
          :rtype: :class:`.table_v2_pb2.ColumnFamily`
          :returns: The converted current object.