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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 post(self, request):
 """Handle a query observer unsubscription request."""

        try:
            observer_id = request.query_params['observer']
            session_id = request.query_params['subscriber']
        except KeyError:
            return response.Response(status=400)

        observer.remove_subscriber(session_id, observer_id)
        return response.Response()