How to check which series can be read/ written

When creating new database users the cluster admin can set readFrom/ writeTo attributes. 

However these attributes are not returned when executing 
`GET /db/anydb/users`.

This makes maintaining granular series permissions a problem because I don't know which permissions a user currently has.

Now I'm wondering: was this by design, or did you just leave this out for a later point in time? Would you accept PR's which add these attributes to UserDetails ?