public boolean clearVectors() {
    boolean _xblockexpression = false;
    {
      final ArrayList<Node> nukeLines = CollectionLiterals.<Node>newArrayList();
      ObservableList<Node> _children = this.gameNodes.getChildren();
      final Procedure1<Node> _function = new Procedure1<Node>() {
        public void apply(final Node child) {
          if ((child instanceof Line)) {
            nukeLines.add(child);
          }
        }
      };
      IterableExtensions.<Node>forEach(_children, _function);
      ObservableList<Node> _children_1 = this.gameNodes.getChildren();
      boolean _removeAll = _children_1.removeAll(nukeLines);
      _xblockexpression = (_removeAll);
    }
    return _xblockexpression;
  }