code: public void set_protocol(String protocol) throws nitro_exception
  	{
  		if (protocol == null || !(protocol.equalsIgnoreCase("http") ||protocol.equalsIgnoreCase("https"))) {
  			throw new nitro_exception("error: protocol value " + protocol + " is not supported");
  		}
  		this.protocol = protocol;
  	}
docs: Sets the protocol.
  @param protocol The protocol to be set.