public void TestPlay()
{
Assert.IsTrue(ppT.IsEmpty);
ppT.Play(d1212);
Assert.IsFalse(ppT.IsEmpty);
Assert.AreEqual(1, ppT.Count);
}
// play on the user train, lets the computer take a move and then enables
// hand pbs so the user can make the next move.
private void myTrainItem_Click(object sender, EventArgs e)
{
Domino d = tableDominos[indexOfDominoInPlay].domino;
tableDominos[indexOfDominoInPlay].picture.Visible = false;
tableDominos.RemoveAt(indexOfDominoInPlay);
userTrain.Play(d);
redraw();
}