code: public <P extends ParaObject> P update(P obj) {
  		if (obj == null) {
  			return null;
  		}
  		return getEntity(invokePatch(obj.getType().concat("/").concat(obj.getId()), Entity.json(obj)), obj.getClass());
  	}
docs: Updates an object permanently. Supports partial updates.
  @param <P> the type of object
  @param obj the object to update
  @return the updated object