// Creates a clone of this object.
Clone()
{
  const testItems = new TestItems();
  let testItem = testItems.Add("NameOne");
  testItem.Sequence = 1;
  testItem = testItems.Add("NameTwo");
  testItem.Sequence = 2;

  // testItems is used as a template.
  const clonedItems = testItems.Clone(testItems);
  let result = 0;
  if (LJC.HasItems(clonedItems))
  {
    result = clonedItems.Count;
  }
  
  // result:
  // 2;

  let dataColumns = new LJCDataColumns();
  dataColumns.AddValue("Name", "NameTwo");
  testItem = testItems.Retrieve(dataColumns);
  result = testItem.Sequence;

  // result:
  // 2
}