/// <summary>
/// Create a reference to a grain that we expect to support the stream consumer extension.
/// </summary>
/// <param name="primaryKey">The primary key of the grain.</param>
/// <param name="grainClassName">The name of the grain class to instantiate.</param>
/// <param name="grainIfaceName">The name of the an IGrain-derived interface that `className` implements (required by MakeGrainReferenceInternal)</param>
/// <returns></returns>
private IStreamConsumerExtension MakeConsumerReference(Guid primaryKey, int implTypeCode)
{
GrainId grainId = GrainId.GetGrainId(implTypeCode, primaryKey);
IAddressable addressable = GrainReference.FromGrainId(grainId);
return(GrainFactory.Cast <IStreamConsumerExtension>(addressable));
}