@Override
    public Set<String> getSupportedExtensions() {
        return Collections.<String>emptySet();
    }
A <code>PKIXCertPathChecker</code> that uses
Online Certificate Status Protocol (OCSP)

See <a href="http://www.ietf.org/rfc/rfc2560.txt">RFC 2560</a>.

@author Jay Kline
xmppserver/src/main/java/org/jivesoftware/openfire/net/OCSPChecker.java