https://developer.mozilla.org/en-US/docs/Web/API/Event/currentTarget
https://developer.mozilla.org/en-US/docs/Web/API/Event/target

event.target is a reference to the object that dispatched the event.
It is different from event.currentTarget when the event handler is called during the bubbling or capturing phase of the event.

modified example provided in cryptstorage.js comments.
corrected error introduced by last commit
(renaming of variable causing errors).
modified tests to comply with cryptstorage.js changes

This storage will transparently compress getAttachment/putAttachment results.
Only text, json, xml mme type are compressed.

Thanks to Lucas Parsy.