<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 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)