/// <summary>
/// Visits the specified callback.
/// </summary>
/// <param name="callback">The callback.</param>
/// <exception cref="ArgumentNullException">The <paramref name="callback"/> is <c>null</c>.</exception>
public void Visit(OnReturnCallback callback)
{
Argument.IsNotNull("callback", callback);
OnReturnCallbackCollection.Add(callback);
}
/// <summary>
/// Visits the specified callback.
/// </summary>
/// <param name="callback">The callback.</param>
/// <exception cref="ArgumentNullException">The <paramref name="callback"/> is <c>null</c>.</exception>
public void Visit(OnReturnCallback callback)
{
Argument.IsNotNull("callback", callback);
OnReturnCallbackCollection.Add(callback);
}