14.1.10 Setting and Reading the WM_PROTOCOLS Property
Xlib provides functions that you can use to set and read
the WM_PROTOCOLS property for a given window.
To set a window's WM_PROTOCOLS property, use
XSetWMProtocols().
To read a window's WM_PROTOCOLS property, use
XGetWMProtocols().
Christophe Tronche, ch@tronche.com