code: public void setSendRefererHeader(boolean send) {
  		if (send == sendRefererHeader) {
  			return;
  		}
  
  		this.sendRefererHeader = send;
  		getConfig().setProperty(SPIDER_SENDER_REFERER_HEADER, this.sendRefererHeader);
  	}
docs: Sets whether or not the "Referer" header should be sent in spider requests.
  
  @param send {@code true} if the "Referer" header should be sent in spider requests, {@code false} otherwise
  @since 2.4.0