in src/main/java/com/googlesource/gerrit/plugins/saml/SamlWebFilter.java [139:144]
private AuthenticatedUser userFromRequest(HttpServletRequest request) {
HttpSession s = request.getSession();
AuthenticatedUser user = (AuthenticatedUser) s.getAttribute(SESSION_ATTR_USER);
if (user == null || user.getUsername() == null) return null;
return user;
}