Set or query the window used as the icon for the window. When the window is iconified, pathName is mapped to serve as its icon and unmapped again when it is de-iconified. An empty string cancels the association. With no argument, return the path name of the current icon window, or an empty string. Not all window managers support icon windows, and the concept is meaningless on non-X11 platforms. wm_iconwindow() is an alias of iconwindow().