public static PaneInfo createPane(boolean isFirst, boolean isLast, Timing timing) {
    checkArgument(isFirst, "Indices must be provided for non-first pane info.");
    return createPane(isFirst, isLast, timing, 0, timing == Timing.EARLY ? -1 : 0);
  }
@Test
  public void testInterned() throws Exception {
    assertSame(
        PaneInfo.createPane(true, true, Timing.EARLY),
        PaneInfo.createPane(true, true, Timing.EARLY));
  }