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 _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)