code: public Set<Object> getWrappedSet(Set<? extends GraphObject> wrappers)
  	{
  		Set<Object> objects = new HashSet<Object>();
  
  		for (GraphObject wrapper : wrappers)
  		{
  			if (wrapper instanceof PhysicalEntityWrapper)
  			{
  				objects.add(((PhysicalEntityWrapper) wrapper).getPhysicalEntity());
  			}
  			else if (wrapper instanceof ControlWrapper)
  			{
  				objects.add(((ControlWrapper) wrapper).getControl());
  			}
  			else if (wrapper instanceof InteractionWrapper)
  			{
  				objects.add(((InteractionWrapper) wrapper).getInteraction());
  			}
  		}
  		return objects;
  	}
docs: Gets the wrapped objects of the given wrappers.
  @param wrappers Wrappers
  @return Wrapped objects