@Override
    public boolean requireAuthentication() {
        return true;
    }
A Kerberos (GSSAPI) implementation of an {@link Authenticator}
This authenticator authenticates and autorizes all clients with a valid service ticket.

@author Marc de Lignie
gremlin-server/src/main/java/org/apache/tinkerpop/gremlin/server/auth/Krb5Authenticator.java