Custom WP-CLI Command

<?php
/**
 * Plugin Name: Custom CLI
 */

 class CustomWPCLI {

    function __construct() {
        add_action( 'cli_init', array( $this, 'mrinal_cli_register_commands' ) );
    }

    function mrinal_cli_register_commands() {
        WP_CLI::add_command( 'github', array( $this, 'http_request' ) );
    }

    function http_request( $user ) {
        $response = WP_CLI\Utils\http_request( 'GET', 'https://api.github.com/users/' . $user[0] );
		update_option( 'github', $response );
    }
 }

 new CustomWPCLI();