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