Do a transactional batch of operations against the same partition key value in Azure Cosmos DB .NET SDK

CosmosTransactionalBatch.cs

using Microsoft.Azure.Cosmos;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;

// Use the transactional batch capability in .NET SDK V3.4 or higher
namespace CosmosBatchSample
{
    class Program
    {
        static async Task Main(string[] args)
        {
            string databaseId = "CosmosDatabase";
            string containerId = "CosmosContainer";

            using (var cosmosClient = new CosmosClient("endpoint", "key"))
            {
                // Get the container
                var container = cosmosClient.GetDatabase(databaseId).GetContainer(containerId);

                // We'll do a transactional batch across these items, which all share the partition key value for Username: "Alice"
                var todoItem1 = new TodoItem()
                {
                    id = Guid.NewGuid().ToString(),
                    Username = "alice",
                    Task = "Get started with Azure Cosmos DB!",
                    Status = "Done"
                };

                var todoItem2 = new TodoItem()
                {
                    id = Guid.NewGuid().ToString(),
                    Username = "alice",
                    Task = "Import data into a container",
                    Status = "In-progress"
                };

                var todoItem3 = new TodoItem()
                {
                    id = Guid.NewGuid().ToString(),
                    Username = "alice",
                    Task = "Run queries against the container ",
                    Status = "Planned"
                };

                // Create and execute the batch of operations
                using (BatchResponse batchResponse = await container.CreateBatch(new PartitionKey("alice"))
                    .CreateItem<TodoItem>(item: todoItem1)
                    .ReplaceItem<TodoItem>(id: todoItem1.id, item: todoItem2)
                    .UpsertItem<TodoItem>(item: todoItem3)
                    .DeleteItem(id: todoItem2.id)
                    .ExecuteAsync())
                {
                    if (!batchResponse.IsSuccessStatusCode)
                    {
                        // Handle and log exception
                        return;
                    }
                    // Look up interested results - eg. via typed access on operation results
                    BatchOperationResult<TodoItem> replaceResult = batchResponse.GetOperationResultAtIndex<TodoItem>(1);
                    TodoItem todoItem2Resource = replaceResult.Resource;

                }
            }
        }
    }
}