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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 get_mfa(self):
 """Return the currently-valid MFA token for this application."""

        token = str(self.totp.now())
        # PyOTP doesn't pre-pad tokens shorter than 6 characters
        # ROTP does, so we have to.
        while len(token) < 6:
            token = '0{}'.format(token)
        return token