Generated tokens should only read once.
Therefore removing the token column at the table view of the manage tokens page and the user's page.
The token should not be able to search.
This class would belong more appropriately within the 'user' API
(core_user) instead of within the 'core' API, since it is
directly related to user data.
Since the class has only just been added to Moodle, now is a good
time to move it.
meirzamoodle