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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 assign(self, bugids, user):
 """ Assign a bug to a user. param bugid: ``int``, bug ID number. param user: ``str``, the login name of the user to whom the bug is assigned returns: deferred that when fired returns True if the change succeeded, False if the change was unnecessary (because the user is already assigned.) """

        payload = {'ids': (bugids,), 'assigned_to': user}
        d = self.call('Bug.update', payload)
        d.addCallback(self._parse_bug_assigned_callback)
        return d