/**
 * Write a string to an output handler.
 *
 * @param   string   $text  The text to display.
 * @param   boolean  $nl    True (default) to append a new line at the end of the output string.
 *
 * @return  $this
 *
 * @since   4.0.0
 * @codeCoverageIgnore
 */
public abstract function out($text = '', $nl = true);