There is an opportunity to set automatic width and height for the list of combo options.
In this case, the size of combo list adjusts to its content.
z.setOptionWidth(200); // sets combo width
z.setOptionHeight(200); // sets combo height
z.enableOptionAutoHeight(1); // enables auto height of combo options
z.enableOptionAutoHeight(0); // disables auto height of combo options
z.enableOptionAutoWidth(1); // enables auto width of combo options
z.enableOptionAutoWidth(0); // disables auto width of combo options