doc: /* Return non-nil if OBJECT is a frame which has not been deleted.
Value is nil if OBJECT is not a live frame. If object is a live
frame, the return value indicates what sort of output device it is
doc: /* Return non-nil if OBJECT is a frame which has not been deleted.
Value is nil if OBJECT is not a live frame. If object is a live
frame, the return value indicates what sort of output device it is