(define-key map "P" 'notmuch-tree-prev-message)
(define-key map (kbd "M-p") 'notmuch-tree-prev-thread)
(define-key map (kbd "M-n") 'notmuch-tree-next-thread)
(define-key map "P" 'notmuch-tree-prev-message)
(define-key map (kbd "M-p") 'notmuch-tree-prev-thread)
(define-key map (kbd "M-n") 'notmuch-tree-next-thread)