docs: def read_wait_cell(self):
          """Read the value of the cell holding the 'wait' value,
  
          Returns the int value of whatever it has, or None if the cell doesn't
          exist.
          """
  
          table_state = self.bt_table.read_row(
              TABLE_STATE,
              filter_=bigtable_row_filters.ColumnRangeFilter(
                  METADATA, WAIT_CELL, WAIT_CELL))
          if table_state is None:
              utils.dbg('No waiting for new games needed; '
                        'wait_for_game_number column not in table_state')
              return None
          value = table_state.cell_value(METADATA, WAIT_CELL)
          if not value:
              utils.dbg('No waiting for new games needed; '
                        'no value in wait_for_game_number cell '
                        'in table_state')
              return None
          return cbt_intvalue(value)