/// <summary>
/// Adds the specified item.
/// </summary>
/// <param name="item">The item.</param>
/// <exception cref="RelationshipInstanceException"></exception>
public void Add(TEntity item)
{
/////
// Input validation.
/////
if (item == null)
{
return;
}
Precheck( );
if (_tracker.All(p => p.Key != item.Id))
{
_tracker.Add((( IEntityInternal )item).MutableId);
}
}