@brief Send a ChangeProperty request for _NET_VIRTUAL_ROOTS
_NET_VIRTUAL_ROOTS, WINDOW[]/32
@param ewmh The per-screen EWMH information
@param screen_nbr The screen number
@param list_len The number of virtual root windows
@param list The virtual root windows
@return Cookie associated with the ChangeProperty _NET_VIRTUAL_ROOTS request
@brief Send a ChangeProperty request for _NET_VIRTUAL_ROOTS
_NET_VIRTUAL_ROOTS, WINDOW[]/32
@param ewmh The per-screen EWMH information @param screen_nbr The screen number @param list_len The number of virtual root windows @param list The virtual root windows @return Cookie associated with the ChangeProperty _NET_VIRTUAL_ROOTS request