Write Test Cases for a Lift

* Open/Close Door:

+ Test Case 1: Verify that the lift door opens when a valid call is made from a floor.

+ Test Case 2: Verify that the lift door closes after a predefined time when open.
* Floor Navigation:

+ Test Case 3: Verify that the lift moves to the selected floor when a user presses the corresponding button inside the lift.

+ Test Case 4: Verify that the lift stops at the selected floor when called from an external floor.
* Emergency Stop:

+ Test Case 5: Verify that pressing the emergency stop button halts the lift immediately.

+ Test Case 6: Verify that the lift can resume operation after the emergency stop button is reset.
* Overload Protection:

+ Test Case 7: Verify that the lift prevents entry when it is already at full capacity.

+ Test Case 8: Verify that the lift does not move if the weight limit is exceeded.
* Door Sensors:

+ Test Case 9: Verify that the door does not close if there is an obstruction detected by sensors.

+ Test Case 10: Verify that the lift does not move if the door is not securely closed.
* Power Failure:

+ Test Case 11: Verify that the lift goes to the nearest floor and opens the door in the event of a power failure.

+ Test Case 12: Verify that the lift maintains its position and prevents any movement during a power failure.
* Emergency Communication:

+ Test Case 15: Verify that the emergency communication system is functional and connects to the building's security or management.