window--dump-frame

window--dump-frame is a compiled Lisp function in `window.el'.

(window--dump-frame &optional WINDOW-OR-FRAME)

Dump WINDOW-OR-FRAME to buffer *window-frame-dump*.
WINDOW-OR-FRAME can be a frame or a window and defaults to the
selected frame. When WINDOW-OR-FRAME is a window, dump that
window's frame. The buffer *window-frame-dump* is erased before
dumping to it.