private TimestampSet buildTimestampSet(double... timestamps) {
    TimestampSet set = new TimestampSet();
    for (double timestamp : timestamps) {
      set.add(timestamp);
    }

    return set;
  }
  @Test
  public void testSetAttributeTimeset() {
    GraphStore store = new GraphStore();
    Column column = store.nodeTable.getColumn("timeset");

    TimestampSet ti = new TimestampSet();
    ti.add(1.0);
    ti.add(2.0);

    NodeImpl node = new NodeImpl("0", store);
    node.setAttribute(column, ti);

    Assert.assertEquals(node.getAttribute(column), ti);
  }