@bobbravo2 can you explain how `plugins_url` is being used here? I don't understand the duplicated `self::PLUGIN_DIR`. Also, here's [another symlink-friendly method](https://github.com/x-team/wp-settings-revisions/blob/master/php/plugin.php#L48-L59) for obtaining the plugin URL:

```php
	/**
	 * Not using plugin_dir_url because it is not symlink-friendly
	 */
	function get_plugin_path_url( $path = null ) {
		$plugin_dirname = basename( dirname( __FILE__ ) );
		$base_dir = trailingslashit( plugin_dir_url( '' ) ) . $plugin_dirname;
		if ( $path ) {
			return trailingslashit( $base_dir ) . ltrim( $path, '/' );
		} else {
			return $base_dir;
		}
	}
```

Perhaps that could just be added to the `Widget_Customizer` class as a static method, and then we could just use `self::get_plugin_path_url( 'widget-customizer-preview.js' )`