/// <summary>
/// Initializes a new instance of the <see cref="AuthDialog"/> class.
/// </summary>
/// <param name="provider">Provides access to core application services.</param>
/// <param name="message">Message received by the bot from the end user.</param>
/// <exception cref="ArgumentNullException">
/// <paramref name="provider"/> is null.
/// or
/// <paramref name="message"/> is null.
/// </exception>
public AuthDialog(IBotProvider provider, IMessageActivity message)
{
provider.AssertNotNull(nameof(provider));
message.AssertNotNull(nameof(message));
this.provider = provider;
conversationReference = message.ToConversationReference();
}