public static @NotNull ActionCallback movePageUp(final @NotNull JTree tree) {
    final int visible = getVisibleRowCount(tree);
    if (visible <= 0){
      return moveHome(tree);
    }
    final int decrement = visible - 1;
    final int row = Math.max(getSelectedRow(tree) - decrement, 0);
    final int top = getFirstVisibleRow(tree) - decrement;
    final int bottom = top + visible - 1;
    return showAndSelect(tree, top, bottom, row, getSelectedRow(tree));
  }
public static @NotNull ActionCallback movePageUp(final @NotNull JTree tree)