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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 send_message(self, sender, um_to_user_list, body):
 """ Send a message from a user, to a user. :param sender: The :class:`User` which sends the message. :param um_to_user_list: A list which elements are :class:`User` to whom the message is for. :param message: String containing the message. """

        msg = self.model(sender=sender,
                         body=body)
        msg.save()

        # Save the recipients
        msg.save_recipients(um_to_user_list)
        msg.update_contacts(um_to_user_list)
        signals.email_sent.send(sender=None,msg=msg)

        return msg