code: public static <V extends VersionedProtocol> V getProxy(Class<V> protocol, InetSocketAddress addr)
  			throws IOException {
  
  		return getProxy(protocol, addr, NetUtils.getDefaultSocketFactory());
  	}
docs: Construct a client-side proxy object with the default SocketFactory
  
  @param protocol
  @param addr
  @return
  @throws IOException