code: def confirm_sign_up(self,confirmation_code,username=None):
          
          if not username:
              username = self.username
          params = {'ClientId': self.client_id,
                    'Username': username,
                    'ConfirmationCode': confirmation_code}
          self._add_secret_hash(params, 'SecretHash')
          self.client.confirm_sign_up(**params)
docs: Using the confirmation code that is either sent via email or text
          message.
          :param confirmation_code: Confirmation code sent via text or email
          :param username: User's username
          :return: