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.
In all cases changes have been kept to a minimum while not making
the code completely horrible. For example, there are many instances
where it would probably be better to rewrite a query entirely, but
I have not done that (in order to reduce the risk of changes).
This was originally intended to be a way for the calling code to specify
data as part of the table construction which could then be used as
appropriate. When the filterset was created the requirement for this
function no longer existed.
Removing this to simplify the API.
Eloy Lafuente (stronk7)