/// <summary>
        /// Adds the provided descriptor of an activity to the builder.
        /// </summary>
        /// <param name="builder">The builder to add to, not null.</param>
        /// <param name="descriptor">The activity descriptor to add.</param>
        /// <returns>This instance, for chaining calls.</returns>
        public static ITaskHubWorkerBuilder AddActivity(
            this ITaskHubWorkerBuilder builder, TaskActivityDescriptor descriptor)
        {
            Check.NotNull(builder, nameof(builder));
            Check.NotNull(descriptor, nameof(descriptor));

            builder.Activities.Add(descriptor);
            return(builder);
        }
 /// <inheritdoc />
 public ITaskHubWorkerBuilder AddActivity(TaskActivityDescriptor descriptor)
 {
     Check.NotNull(descriptor, nameof(descriptor));
     _activities.Add(descriptor);
     return(this);
 }