code: private void removeSlotRequestFromSlot(SlotID slotId, AllocationID allocationId) {
  		TaskManagerSlot taskManagerSlot = slots.get(slotId);
  
  		if (null != taskManagerSlot) {
  			if (taskManagerSlot.getState() == TaskManagerSlot.State.PENDING && Objects.equals(allocationId, taskManagerSlot.getAssignedSlotRequest().getAllocationId())) {
  
  				TaskManagerRegistration taskManagerRegistration = taskManagerRegistrations.get(taskManagerSlot.getInstanceId());
  
  				if (taskManagerRegistration == null) {
  					throw new IllegalStateException("Trying to remove slot request from slot for which there is no TaskManager " + taskManagerSlot.getInstanceId() + " is registered.");
  				}
  
  				// clear the pending slot request
  				taskManagerSlot.clearPendingSlotRequest();
  
  				updateSlotState(taskManagerSlot, taskManagerRegistration, null, null);
  			} else {
  				LOG.debug("Ignore slot request removal for slot {}.", slotId);
  			}
  		} else {
  			LOG.debug("There was no slot with {} registered. Probably this slot has been already freed.", slotId);
  		}
  	}
docs: Removes a pending slot request identified by the given allocation id from a slot identified
  by the given slot id.
  
  @param slotId identifying the slot
  @param allocationId identifying the presumable assigned pending slot request