public void set_keep_above (bool setting)
Set if this must be kept above other windows.
If the window was already above, then this function does nothing.
On X11, asks the window manager to keep this above, if the window manager supports this operation. Not all window managers support this, and some deliberately ignore it or don’t have a concept of “keep above”; so you can’t rely on the window being kept above. But it will happen with most standard window managers, and GDK makes a best effort to get it to happen.
a toplevel Window
whether to keep this above other windows