transaction manager

#! /usr/bin/env python

class TransactionContext(object):
    def __init__(self, transaction):
        self.transaction = transaction
        self.bigip = transaction._meta_data['bigip']
        self.session = self.bigip._meta_data['icr_session']
    
    def __enter__(self):
        self.transaction.create(json={})
        self.session.headers.update(
            'X-F5-REST-Coordination-Id': self.transaction.transId
        )
        return self.bigip
    
    def __exit__(self, exc_type, exc_value, exc_tb):
        self.session.headers = dict()
        if exc_tb is None:
            self.transaction.submit()
        else:
            raise