public static function isNewline() {
    static $callback = NULL;
    if (!$callback) {
      $callback = function (Node $node) {
        return $node instanceof WhitespaceNode && $node->getNewlineCount() > 0;
      };
    }
    return $callback;
  }
public static function isNewline() {
    static $callback = NULL;
    if (!$callback) {
      $callback = function (Node $node) {
        return $node instanceof WhitespaceNode && $node->getNewlineCount() > 0;
      };
    }
    return $callback;
  }
public static function isNewline ( ) { static $ callback = NULL ; if ( ! $ callback ) { $ callback = function ( Node $ node ) { return $ node instanceof WhitespaceNode && $ node -> getNewlineCount ( ) > 0 ; } ; } return $ callback ; }
Callback to match whitespace containing newlines.

@return callable
Callback to match whitespace containing newlines .