docs: def delete(self, table, identifier):
          """Deletes a table row by given identifier.
  
          :param table: the expression of the table to update quoted or unquoted
          :param identifier: the delete criteria; a dictionary containing column-value pairs
          :return: the number of affected rows
          :rtype: int
          """
          with self.locked() as conn:
              return conn.delete(table, identifier)