code: def flush(bank, key=None):
      '''
      Remove the key from the cache bank with all the key content.
      '''
      _init_client()
      query = "DELETE FROM {0} WHERE bank='{1}'".format(_table_name, bank)
      if key is not None:
          query += " AND etcd_key='{0}'".format(key)
  
      cur, _ = run_query(client, query)
      cur.close(f flush(bank, key=None):
      '''
      Remove the key from the cache bank with all the key content.
      '''
      _init_client()
      query = "DELETE FROM {0} WHERE bank='{1}'".format(_table_name, bank)
      if key is not None:
          query += " AND etcd_key='{0}'".format(key)
  
      cur, _ = run_query(client, query)
      cur.close()
docs: Remove the key from the cache bank with all the key content.