When using Facebook-Test-Java-API to grab test users of my app, why do some users have their name/email missing? -

i'm using following library: https://github.com/jayway/facebook-test-java-api information test users in private facebook app. can retrieve of test users of app, when use facebooktestaccount.getuserdetails(), accounts (~20%) test account's name and/or email missing.

is problem facebook-test-java-api or lack permission view data? when view test users of app via facebook's developer app dashboard, can see name/email test user accounts.

as far know, of these test user accounts generated same way via facebook's test user creation tool.