Add exception annotation to openDepartmentGateForCommand method for clarity

services/nginx/app/modules/selfserve/traits/selfserve_lane_command_t.php

@@ -222,6 +222,9 @@ trait selfserve_lane_command_t
             : $department_gates->getExitGate($department_id);
     }
 
+    /**
+     * @throws Exception
+     */
     protected function openDepartmentGateForCommand(department_gates_o $gate): void
     {
         $gate->openGate();