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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def commit_version(self, version, msg=None):
 """ Add tag, commit, and push changes """


        assert version not in self.versions, 'Will not overwrite a version name.'

        if not msg:
            feat, targ = self.training_data
            msg = 'Training set has {0} examples. '.format(len(feat))
            feat, targ = self.testing_data
            msg += 'Testing set has {0} examples.'.format(len(feat))

        cmd = self.repo.commit(m=msg, a=True)
        cmd = self.repo.tag(version)
        cmd = self.repo.checkout('master')
        self.update()
        cmd = self.repo.merge('working')
        cmd = self.repo.branch('working', d=True)
        self.set_version(version)

        try:
            stdout = self.repo.push('origin', 'master', '--tags').stdout
            logger.info(stdout)
        except:
            logger.info('Push not working. Remote not defined?')