/// <summary>
/// Start listening for CloudEvents and handle them using the specified callback function.
/// <para>
/// The <typeparamref name="TCloudEvent"/> type <em>must</em> define a constructor with the
/// exact parameters <c>(<see cref="IReceiverMessage"/>, <see cref="IProtocolBinding"/>)
/// </c>. A <see cref="MissingMemberException"/> is immediately thrown if the class does
/// not define such a constructor.
/// </para>
/// </summary>
/// <param name="receiver">The receiver to start.</param>
/// <param name="onEventReceivedAsync">
/// A function that is invoked when a CloudEvent is received.
/// </param>
/// <param name="protocolBinding">
/// The <see cref="IProtocolBinding"/> used to map <see cref="IReceiverMessage"/> headers to
/// CloudEvent attributes.
/// </param>
/// <exception cref="ArgumentNullException">
/// If <paramref name="receiver"/> or <paramref name="onEventReceivedAsync"/> is <see
/// langword="null"/>.
/// </exception>
/// <exception cref="MissingMemberException">
/// If the <typeparamref name="TCloudEvent"/> class does not define a public constructor
/// with the exact parameters <c>(<see cref="IReceiverMessage"/>, <see cref=
/// "IProtocolBinding"/>)</c>.
/// </exception>
public static void Start <TCloudEvent>(this IReceiver receiver,
Func <TCloudEvent, IReceiverMessage, Task> onEventReceivedAsync, IProtocolBinding protocolBinding = null)
where TCloudEvent : CloudEvent
{
if (receiver is null)
{
throw new ArgumentNullException(nameof(receiver));
}
if (onEventReceivedAsync is null)
{
throw new ArgumentNullException(nameof(onEventReceivedAsync));
}
if (!MessageConstructor.Exists(typeof(TCloudEvent)))
{
throw MissingReceiverConstructor(typeof(TCloudEvent));
}
receiver.Start(message => onEventReceivedAsync(message.To <TCloudEvent>(protocolBinding), message));
}