kinsta-widget.php

<?php
/**
 * @package Kinsta_widget
 * @version 1.0
 */
/*
Plugin Name: Kinsta Widget
Plugin URI: http://wordpress.org/extend/plugins/#
Description: This is an example plugin 
Author: Your Name
Version: 1.0
Author URI: http://example.com/
*/

class Kinsta_Widget extends WP_Widget {

	/**
	 * Sets up the widgets name etc
	 *
	 * @link https://developer.wordpress.org/reference/classes/wp_widget/__construct/
	 * @see https://developer.wordpress.org/reference/functions/wp_register_sidebar_widget/
	 *
	 */
	public function __construct() {}

	/**
	 * Outputs the content of the widget on front-end
	 *
	 * @param array $args Widget arguments 
	 * @param array $instance 
	 *
	 * @link https://developer.wordpress.org/reference/classes/wp_widget/widget/
	 */
	public function widget( $args, $instance ) {}

	/**
	 * Outputs the options form on admin
	 *
	 * @param array $instance The widget options
	 *
	 * @link https://developer.wordpress.org/reference/classes/wp_widget/form/
	 */
	public function form( $instance ) {}

	/**
	 * Processing widget options on save
	 *
	 * @param array $new_instance The new options
	 * @param array $old_instance The previous options
	 *
	 * @link https://developer.wordpress.org/reference/classes/wp_widget/update/
	 */
	public function update( $new_instance, $old_instance ) {}
}

// register Kinsta_Widget
add_action( 'widgets_init', function(){
	register_widget( 'Kinsta_Widget' );
});