code: def commit_transaction(self):
          
          with self._transaction_lock:
              local = self._transaction_local
              if not local.pipes:
                  raise ValueError('No transaction is currently active.')
              return local.commit()
docs: Commit the currently active transaction (Pipeline). If no
          transaction is active in the current thread, an exception
          will be raised.
  
          :returns: The return value of executing the Pipeline.
          :raises: ``ValueError`` if no transaction is active.