@Override
    public String handle(final Credential credential, final Ticket proxyGrantingTicket) {
        return null;
    }
Dummy ProxyHandler that does nothing. Useful for CAS 1.0 compliance as CAS
1.0 has no proxying capabilities.

@author Scott Battaglia
@since 3.0.0
core/cas-server-core-tickets-api/src/main/java/org/apereo/cas/ticket/proxy/support/Cas10ProxyHandler.java