    void explain(OperationContext* opCtx,
                 ExplainOptions::Verbosity verbosity,
                 BSONObjBuilder* result) override {
        uassertStatusOK(_command->explain(opCtx, *_request, verbosity, result));
    }
    void explain(OperationContext* opCtx,
                 ExplainOptions::Verbosity verbosity,
                 BSONObjBuilder* result) override {
        uassertStatusOK(_command->explain(opCtx, *_request, verbosity, result));
    }