	/**
	 * Should we add debug lines
	 *
	 * @since 3.2.0
	 **/
	private static $add = 'check';

	/**
	 * Set the line number in comments
	 *
	 * @param   int     $nr     The line number
	 * @param   string  $class  The class name
	 *
	 * @return  string
	 * @since 3.2.0
	 */
	public static function _(int $nr, string $class): string
	{
		if (self::add())
		{
			return ' [' . $class . ' ' . $nr . ']';
		}

		return '';
	}

	/**
	 * Check if we should add the line number
	 *
	 * @return  bool
	 * @since 3.2.0
	 */
	private static function add(): bool
	{
		if (!is_bool(self::$add))
		{
			self::init();
		}

		return self::$add;
	}

	/**
	 * The constructor for add
	 *
	 * @return  void
	 * @since 3.2.0
	 */
	private static function init()
	{
		self::$add = Compiler::_('Config')->debug_line_nr;
	}
