code: private void removeSlot(SlotID slotId) {
  		TaskManagerSlot slot = slots.remove(slotId);
  
  		if (null != slot) {
  			freeSlots.remove(slotId);
  
  			if (slot.getState() == TaskManagerSlot.State.PENDING) {
  				// reject the pending slot request --> triggering a new allocation attempt
  				rejectPendingSlotRequest(
  					slot.getAssignedSlotRequest(),
  					new Exception("The assigned slot " + slot.getSlotId() + " was removed."));
  			}
  
  			AllocationID oldAllocationId = slot.getAllocationId();
  
  			if (oldAllocationId != null) {
  				fulfilledSlotRequests.remove(oldAllocationId);
  
  				resourceActions.notifyAllocationFailure(
  					slot.getJobId(),
  					oldAllocationId,
  					new FlinkException("The assigned slot " + slot.getSlotId() + " was removed."));
  			}
  		} else {
  			LOG.debug("There was no slot registered with slot id {}.", slotId);
  		}
  	}
docs: Removes the given slot from the slot manager.
  
  @param slotId identifying the slot to remove