@brief Send GetProperty request to get _NET_SUPPORTING_WM_CHECK root window property
@param ewmh The information relative to EWMH @param screen_nbr The screen number @return The _NET_SUPPORTING_WM_CHECK cookie of the GetProperty request
See Implementation
@brief Send GetProperty request to get _NET_SUPPORTING_WM_CHECK root window property
@param ewmh The information relative to EWMH @param screen_nbr The screen number @return The _NET_SUPPORTING_WM_CHECK cookie of the GetProperty request