docs: SharedSlot allocateSharedSlot(AbstractID groupId){
  		if (isAlive()) {
  			SharedSlot slot = new SharedSlot(
  				getOwner(),
  				getTaskManagerLocation(),
  				subSlots.size(),
  				getTaskManagerGateway(),
  				assignmentGroup,
  				this,
  				groupId);
  			subSlots.add(slot);
  			return slot;
  		}
  		else {
  			return null;
  		}
  	}