### Question:
SimpleSlot extends Slot implements LogicalSlot { @Override public CompletableFuture<?> releaseSlot(@Nullable Throwable cause) { if (!isCanceled()) { final CompletableFuture<?> terminationFuture; if (payload != null) { payload.fail(cause != null ? cause : new FlinkException("TaskManager was lost/killed: " + getTaskManagerLocation())); terminationFuture = payload.getTerminalStateFuture(); } else { terminationFuture = CompletableFuture.completedFuture(null); } terminationFuture.whenComplete( (Object ignored, Throwable throwable) -> { if (getParent() == null) { if (markCancelled()) { getOwner().returnAllocatedSlot(this).whenComplete( (value, t) -> { if (t != null) { releaseFuture.completeExceptionally(t); } else { releaseFuture.complete(null); } }); } } else { getParent().releaseChild(this); releaseFuture.complete(null); } }); } return releaseFuture; } SimpleSlot(
		SlotOwner owner, TaskManagerLocation location, int slotNumber,
		TaskManagerGateway taskManagerGateway);  SimpleSlot(
			SlotOwner owner,
			TaskManagerLocation location,
			int slotNumber,
			TaskManagerGateway taskManagerGateway,
			@Nullable SharedSlot parent,
			@Nullable AbstractID groupID);  SimpleSlot(SlotContext slotContext, SlotOwner owner, int slotNumber);  SimpleSlot(SharedSlot parent, SlotOwner owner, int slotNumber, AbstractID groupID); private  SimpleSlot(
			SlotContext slotContext,
			SlotOwner owner,
			int slotNumber,
			@Nullable SharedSlot parent,
			@Nullable AbstractID groupID); @Override int getNumberLeaves(); @Override boolean tryAssignPayload(Payload payload); @Nullable @Override Payload getPayload(); Locality getLocality(); void setLocality(Locality locality); @Override CompletableFuture<?> releaseSlot(@Nullable Throwable cause); @Override int getPhysicalSlotNumber(); @Override AllocationID getAllocationId(); @Override SlotRequestId getSlotRequestId(); @Nullable @Override SlotSharingGroupId getSlotSharingGroupId(); @Override String toString();  }### Answer:
@Test public void testStateTransitions() { try { { SimpleSlot slot = getSlot(); assertTrue(slot.isAlive()); slot.releaseSlot(); assertFalse(slot.isAlive()); assertTrue(slot.isCanceled()); assertTrue(slot.isReleased()); } { SimpleSlot slot = getSlot(); assertTrue(slot.isAlive()); slot.markCancelled(); assertFalse(slot.isAlive()); assertTrue(slot.isCanceled()); assertFalse(slot.isReleased()); slot.markReleased(); assertFalse(slot.isAlive()); assertTrue(slot.isCanceled()); assertTrue(slot.isReleased()); } } catch (Exception e) { e.printStackTrace(); fail(e.getMessage()); } }