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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 editpermissions_user_view(self, request, user_id, forum_id=None):
 """ Allows to edit user permissions for the considered forum. The view displays a form to define which permissions are granted for the given user for the considered forum. """

        user_model = get_user_model()
        user = get_object_or_404(user_model, pk=user_id)
        forum = get_object_or_404(Forum, pk=forum_id) if forum_id else None

        # Set up the context
        context = self.get_forum_perms_base_context(request, forum)
        context['forum'] = forum
        context['title'] = '{} - {}'.format(_('Forum permissions'), user)
        context['form'] = self._get_permissions_form(
            request, UserForumPermission, {'forum': forum, 'user': user},
        )

        return render(request, self.editpermissions_user_view_template_name, context)