Sets hints about the window management functions to make available via buttons on the window frame.
On the X backend, this function sets the traditional Motif window manager hint for this purpose. However, few window managers do anything reliable or interesting with this hint. Many ignore it entirely.
functions argument is the logical OR of values from the WMFunction
enumeration. If the bitmask includes ALL, then the other bits indicate which
functions to disable; if it doesn’t include ALL, it indicates which functions
a toplevel Window
bitmask of operations to allow on this