Note: this function can remove any object within an UIListBox, even if it wasn't dynamically added with AddListBoxRow but part of the original GUI. This can be useful for creators of custom UIs, because it allows a coder to put different kinds of objects in a listbox, and then use this function to weed out the ones that are not needed. AddListBoxRow does not work for this, since it can only add one type of row, as specified in the GUI (the "prototype" row). * Added in Patch 1.13