<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def rollback(self, revision):
 """ Rollsback the currently deploy lambda code to a previous revision. """


        print("Rolling back..")

        self.zappa.rollback_lambda_function_version(
            self.lambda_name, versions_back=revision)
        print("Done!")