/// <summary>
/// Adds the specified <see cref="DeleteCollection"/> to <see cref="Updates"/>.
/// </summary>
/// <param name="update">The <c>Delete</c> to add.</param>
/// <exception cref="ArgumentNullException">update is null.</exception>
/// <exception cref="InvalidOperationException">
/// update belongs to another <see cref="Element"/>.
/// </exception>
public void AddUpdate(DeleteCollection update)
{
this.AddChild(update);
}
/// <summary>
/// Adds the specified <see cref="DeleteCollection"/> to <see cref="Updates"/>.
/// </summary>
/// <param name="update">The <c>Delete</c> to add.</param>
/// <exception cref="ArgumentNullException">update is null.</exception>
/// <exception cref="InvalidOperationException">
/// update belongs to another <see cref="Element"/>.
/// </exception>
public void AddUpdate(DeleteCollection update)
{
this.AddAsChild(this.updates, update);
}