/// <summary>
/// Initializes a new instance of the <see cref="AsyncElasticsearchProjector"/> class.
/// </summary>
/// <param name="handlers">The handlers.</param>
/// <exception cref="System.ArgumentNullException">Thrown when <paramref name="handlers"/> is <c>null</c>.</exception>
public AsyncElasticsearchProjector(ElasticsearchProjectionHandler[] handlers)
{
if (handlers == null) throw new ArgumentNullException("handlers");
_handlers = handlers.
GroupBy(handler => handler.Message).
ToDictionary(@group => @group.Key, @group => @group.ToArray());
}
