in src/main/java/org/apache/sling/jcr/base/internal/mount/ProxyRepository.java [114:126]
public Session wrap(Session session) throws RepositoryException {
if (session instanceof ProxySession) {
return session;
}
Map<String, Object> attributes = new HashMap<>();
attributes.put(RepositoryMount.PARENT_SESSION_KEY, session);
Session mountSession = ((JackrabbitRepository) mount).login(new SimpleCredentials(session.getUserID(), new char[0]),session.getWorkspace().getName(), attributes );
return session instanceof JackrabbitSession ?
new ProxyJackrabbitSession(this, (JackrabbitSession) session, mountSession, this.mountPoints) :
new ProxySession<>(this, session, mountSession, this.mountPoints);
}