(define-key pdf-outline-buffer-mode-map (kbd "C-o") nil)
(define-key pdf-outline-buffer-mode-map (kbd "i") 'outline-toggle-children)
(define-key pdf-outline-buffer-mode-map (kbd "j") 'next-line)
(define-key pdf-outline-buffer-mode-map (kbd "C-o") nil)
(define-key pdf-outline-buffer-mode-map (kbd "i") 'outline-toggle-children)
(define-key pdf-outline-buffer-mode-map (kbd "j") 'next-line)