code: def to_pb(self):
          
          chain = data_v2_pb2.RowFilter.Chain(
              filters=[row_filter.to_pb() for row_filter in self.filters]
          )
          return data_v2_pb2.RowFilter(chain=chain)
docs: Converts the row filter to a protobuf.
  
          :rtype: :class:`.data_v2_pb2.RowFilter`
          :returns: The converted current object.