Require a given number of fresh games to be played.

        Args:
          number_fresh:  integer, number of new fresh games needed

        Increments the cell `table_state=metadata:wait_for_game_number`
        by the given number of games.  This will cause
        `self.wait_for_fresh_games()` to block until the game
        counter has reached this number.

def require_fresh_games(self, number_fresh):
        """Require a given number of fresh games to be played.

        Args:
          number_fresh:  integer, number of new fresh games needed

        Increments the cell `table_state=metadata:wait_for_game_number`
        by the given number of games.  This will cause
        `self.wait_for_fresh_games()` to block until the game
        counter has reached this number.
        """
        latest = self.latest_game_number
        table_state = self.bt_table.row(TABLE_STATE)
        table_state.set_cell(METADATA, WAIT_CELL, int(latest + number_fresh))
        table_state.commit()
        print("== Setting wait cell to ", int(latest + number_fresh), flush=True)