Sample WP CLI class

migration-cli.php

<?php
/*
Plugin Name: WDS Migration
Plugin URI: 
Description: Migration via custom WP CLI commands.
Version: 1.0
Author: Lax Mariappan
Author URI: https://www.webdevstudios.com
Text Domain: migrate
*/
 

/**
 * Migration class with commands and helper functions.
 *
 * @since 1.0
 */
class WDS_Migration {

/**
 * Export content.
 *
 * @return void
 * @since  1.0
 * @author Lax Mariappan <lax@webdevstudios.com>
 */
public function export(){
    \WP_CLI::log( 'Export' );
}

/**
 * Import content.
 *
 * @return void
 * @since  1.0
 * @author Lax Mariappan <lax@webdevstudios.com>
 */
public function import(){
    $site = $this->get_site_name();
   \WP_CLI::line( \WP_CLI::colorize( '%y imported ' . $site . ' site content, check logs for errors. %n' ) );
}

/**
 * Get current site name.
 *
 * @return void
 * @since  1.0
 * @author Lax Mariappan <lax@webdevstudios.com>
 */
private function get_site_name(){
    $full_url  = get_site_url( get_current_blog_id() );
    $site_name = basename( $full_url );
    return $site_name;
}

}

function wds_cli_register_commands() {
    \WP_CLI::add_command( 'migrate', 'WDS_Migration' );
}

add_action( 'cli_init', 'wds_cli_register_commands' );