/// <summary>
/// Enqueues a copy of the vertical track arc to move one layer.
/// </summary>
/// <param name='forMotor'>
/// The motor to move.
/// </param>
/// <param name='toQueue'>
/// The queue to fill.
/// </param>
void NextLayer(PrinterMotor forMotor, List <Arc> toQueue)
{
Arc anArc = new Arc(m_vertTrackArc);
anArc.motor = forMotor;
forMotor.Step(anArc.length);
toQueue.Add(anArc);
Contract.Assert(toQueue.Count == 1, @"Expected 1, not {0} vertical arc{1}",
toQueue.Count, Text.S(toQueue.Count));
}
