def execute(self):
<EOL>self.executed_at = now()<EOL>self.save()<EOL>with transaction.atomic():<EOL><INDENT>ret = BillingAgreement.execute(self.id)<EOL>ret.user = self.user<EOL>ret.save()<EOL>self.executed_agreement = ret<EOL>self.save()<EOL><DEDENT>return ret<EOL>
Execute the PreparedBillingAgreement by creating and executing a
matching BillingAgreement.