@Override
    public boolean supports(final Credential credential) {
        return credential instanceof SpnegoCredential;
    }
Implementation of an AuthenticationHandler for SPNEGO supports. This Handler
support both NTLM and Kerberos. NTLM is disabled by default.

@author Arnaud Lesueur
@author Marc-Antoine Garrigue
@author Scott Battaglia
@author Marvin S. Addison
@since 3.1
support/cas-server-support-spnego/src/main/java/org/apereo/cas/support/spnego/authentication/handler/support/JcifsSpnegoAuthenticationHandler.java