Authentication of endpoints in federated queries

[Zak Mc Kracken]

Hello everyone,

I need a federated SPARQL query, where the SERVICE endpoint requires 
basic HTTP authentication (the one that is based on .htaccess and works 
by sending user/pass to the server).

I cannot understand if this is possible in Jena and how. Some 
documentation mentions the simpler case where you authenticate against 
the main endpoint 
(https://jena.apache.org/documentation/query/http-auth.html), does this 
apply to SERVICE too? If yes, do I just need the ServiceAuthenticator? 
(By the way, the link to 
http://jena.apache.org/documentation/javadoc/arq/org/apache/jena/atlas/web/auth/ServiceAuthenticator.html 
is broken in that page, I found it via browsing the code).

Thanks in advance,
Marco.