Factory.php

<?php 
namespace Instagram_Helper;

/**
* 
*/
class Factory {
	
	private static $classes = array(
		'Client'        => 'client',
		'Data_Manager'  => 'data_manager',
		'Carbon_Helper' => 'carbon_helper',
		'Posts_Store'   => 'posts_store',
	);

	public static function create( $class, $user_conig = array() ){
	
		$instance = array_search( $class, self::$classes );

		if ( ! $instance ) {
			return new \WP_Error( 'invalid_class_abbreviation', __( 'Please provide a valid class abbreviation for the factory. Possible values are "client", "data_manager", "carbon_helper", "post_store" ', 'crb' ));
		} 

		$instance = __NAMESPACE__ . '\\' . $instance;

		return new $instance( $user_conig );
	}
}