<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def tag(**tags):
 """ Tags current transaction. Both key and value of the tag should be strings. """

    transaction = execution_context.get_transaction()
    if not transaction:
        error_logger.warning("Ignored tags %s. No transaction currently active.", ", ".join(tags.keys()))
    else:
        transaction.tag(**tags)