code: public PropertyRequest addProperty(ElementDescriptor<?> property)
  	{
  		if (mProp == null)
  		{
  			mProp = new HashMap<ElementDescriptor<?>, Object>(16);
  		}
  		mProp.put(property, null);
  		return this;
  	}
docs: Add another property to the list of requested properties.
  
  @param property
  The property to request from the server.
  @return This instance.