Coverity static analysis: Dereference null return value in ServerAuthenticationContext (Elytron)

if (log.isTraceEnabled()) {
                log.tracef("Authorizing principal %s.", authenticationPrincipal.getName());
                log.tracef("Authorizing against the following attributes: %s => %s",
                        authorizationIdentity.getAttributes().keySet(), authorizationIdentity.getAttributes().values());
            }

        @Override
        public AuthorizationIdentity getAuthorizationIdentity() throws RealmUnavailableException {
            if (exists()) {
                return new AuthorizationIdentity() {
                    @Override
                    public Attributes getAttributes() {
                        return claims;
                    }
                };
            }

            return null;
        }