Looking at the 'AuthenticationEndpoint' I noticed that the "org.jboss.aerogear.security.auth.AuthenticationManager" class ([1]) is used without parameterization:
https://github.com/aerogear/aerogear-unifiedpush-server/blob/master/src/main/java/org/jboss/aerogear/unifiedpush/rest/security/AuthenticationEndpoint.java#L41-L42

This works fine, but let's use a parameter.

The AG-Sec-PL JAR comes with a default implemention that uses 'Agent' as its parameterized type