A temporary Plugin I created to keep small php snippets independent of theme functions.php file

MyTemporaryPlugin.php

<?php
/**
 * Plugin Name: MyTemporaryPlugin
 * Plugin URI: http://OsamaShabrez.com
 * Description: This is small temporary plugin created to keep small php codes idependent of theme or other plugin files
 * Version: 1.0.1
 * Author: Muhammad Osama Shabrez
 * Author URI: http://OsamaShabrez.com
 * Network: false
 * License: GPL2
 */

/*  Copyright 2015  Muhammad Osama Shabrez  (email : Contact@OsamaShabrez.com)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2, as 
    published by the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/
    defined('ABSPATH') or die("No script bitches please!");

	//Block Referal URL exploit for Comments
	function verify_comment_referer_tempplugin() {
	    if (!wp_get_referer()) {
	        wp_die( __('You cannot post comment at this time, may be you need to enable referrers in your browser.') );
	    }
	}
	add_action('check_comment_flood', 'verify_comment_referer_tempplugin');


	// Create Nonce
	function add_nonce_field_to_comment_form() {
	    wp_nonce_field('comment_form_nonce_field');
	}
	 
	// Include Nonce To Comment Form
	add_action('comment_form', 'add_nonce_field_to_comment_form');
	 
	// Check Nonce Field Validity
	function check_nonce_field_on_comment_form() {
	    if (!wp_verify_nonce($_REQUEST['_wpnonce'], 'comment_form_nonce_field')) {
	        die('Nonce Check Failed - Killing Request');
	    }
	}
	 
	// Add Nonce Check To Comment Form Post
	add_action('pre_comment_on_post', 'check_nonce_field_on_comment_form');
?>