docs: def _write_move_counts(self, sess, h):
          """Add move counts from the given histogram to the table.
  
          Used to update the move counts in an existing table.  Should
          not be needed except for backfill or repair.
  
          Args:
            sess:  TF session to use for doing a Bigtable write.
            tf_table:  TF Cloud Bigtable to use for writing.
            h:  a dictionary keyed by game row prefix ("g_0023561") whose values
               are the move counts for each game.
          """
          def gen():
              for k, v in h.items():
                  # The keys in the histogram may be of type 'bytes'
                  k = str(k, 'utf-8')
                  vs = str(v)
                  yield (k.replace('g_', 'ct_') + '_%d' % v, vs)
                  yield (k + '_m_000', vs)
          mc = tf.data.Dataset.from_generator(gen, (tf.string, tf.string))
          wr_op = self.tf_table.write(mc,
                                      column_families=[METADATA],
                                      columns=[MOVE_COUNT])
          sess.run(wr_op)