public virtual void RemoveWaggonAt(int index)
{
Contract.Requires <ArgumentOutOfRangeException>(index >= 0 && index < Waggons.Count());
Contract.Assume(index < Waggons.Count());
this._waggons.RemoveAt(index);
}
/// <summary>
/// Moves a waggon at the specified index one step up.
/// </summary>
/// <param name="index">The index of the waggon.</param>
public virtual void MoveWaggonUpAt(int index)
{
Contract.Requires <ArgumentOutOfRangeException>(index >= 0 && index < Waggons.Count());
Contract.Assume(index < this._waggons.Count);
Waggon waggon = this._waggons[index];
this._waggons.RemoveAt(index);
this._waggons.Insert(index - 1, waggon);
}