code: synchronized public void setEnabledProtocols(String[] protocols) {
          enabledProtocols = new ProtocolList(protocols);
          if ((handshaker != null) && !handshaker.activated()) {
              handshaker.setEnabledProtocols(enabledProtocols);
          }
      }
docs: Controls which protocols are enabled for use on
  this connection.  The protocols must have been listed by
  getSupportedProtocols() as being supported.
  
  @param protocols protocols to enable.
  @exception IllegalArgumentException when one of the protocols
  named by the parameter is not supported.