Subsequent editing commands apply to its selected window.
Optional argument NORECORD means to neither change the order of
recently selected windows nor the buffer list.
The selection of FRAME lasts until the next time the user does
something to select a different frame, or until the next time
this function is called. If you are using a window system, the
previously selected frame may be restored as the selected frame
when returning to the command loop, because it still may have
the window system's input focus. On a text terminal, the next
redisplay will display FRAME.
This function returns FRAME, or nil if FRAME has been deleted. (fn FRAME &optional NORECORD)