@Override
    public boolean supports(final Credential credential) {
        return credential instanceof HttpBasedServiceCredential;
    }
Class to validate the credential presented by communicating with the web
server and checking the certificate that is returned against the hostname,
etc.
<p>
This class is concerned with ensuring that the protocol is HTTPS and that a
response is returned. The SSL handshake that occurs automatically by opening
a connection does the heavy process of authenticating.

@author Scott Battaglia
@since 3.0.0
core/cas-server-core-authentication-api/src/main/java/org/apereo/cas/authentication/handler/support/ProxyAuthenticationHandler.java