docs: def delete(self, table, where=None):
          """Delete existing rows from a table."""
          if where:
              where_key, where_val = where
              query = "DELETE FROM {0} WHERE {1}='{2}'".format(wrap(table), where_key, where_val)
          else:
              query = 'DELETE FROM {0}'.format(wrap(table))
          self.execute(query)
          return True