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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 new_message(self, resource=None):
 """ Creates a new message to be sent or stored :param str resource: Custom resource to be used in this message (Defaults to parent main_resource) :return: New empty message :rtype: Message """

        return Message(parent=self, main_resource=resource, is_draft=True)