If you supply auth_key, It will be written to "~/.pushbulletkey"
umx_pb_note
(auth_key="mykeystring")
once it exists there, you do not need to store it in code, so code is sharable.
You can get your authorization key at https://www.pushbullet.com in
the "account" section.
Note: You can show the existing stored key using "GET"