code: public static function load_class( $class_name = NULL ) {
  
  		// if spl_autoload_register not exist
  		if ( NULL === $class_name ) {
  			// load required classes
  			foreach ( glob( dirname( __FILE__ ) . '/*.php' ) as $path ) {
  				require_once $path;
  			}
  		} else {
  			if ( 0 !== strpos( $class_name, 'Iac_' ) )
  				return FALSE;
  
  			// if param have a class string
  			$path = dirname( __FILE__ ) . '/class-' . $class_name . '.php';
  			if ( file_exists( $path ) ) {
  				require_once $path;
  
  				return TRUE;
  			}
  		}
  
  		return FALSE;
  	}
docs: autoloader for the classes
  
  @since 0.0.5
  
  @param NULL|string $class_name
  
  @return bool