/** Which undo history step a key press asks for: Cmd/Ctrl+Z, Cmd/Ctrl+Shift+Z or Cmd/Ctrl+Y, never while typing in a field. */
export declare function historyStepForKey(event: Pick<KeyboardEvent, "key" | "metaKey" | "ctrlKey" | "altKey" | "shiftKey" | "target">): "undo" | "redo" | null;