public CosmosContainer Convert(CosmosAttribute attribute)
        {
            if (attribute == null)
            {
                throw new ArgumentNullException(nameof(attribute));
            }

            ICosmosService service = configProvider.GetService(
                configProvider.ResolveConnectionString(attribute.ConnectionStringSetting),
                attribute.ApplicationName,
                attribute.ApplicationRegion);

            if (attribute.CreateIfNotExists)
            {
                var context = new CosmosContext
                {
                    ResolvedAttribute = attribute,
                    Service           = service
                };

                CosmosUtility.CreateDatabaseAndContainerNameIfNotExistAsync(context).Wait();
            }

            return(service.GetContainer(attribute.DatabaseName, attribute.ContainerName));
        }
        public async Task AddAsync(T item, CancellationToken cancellationToken = default)
        {
            bool create = false;

            try
            {
                await UpsertDocument(cosmosContext, item);
            }
            catch (Exception ex)
            {
                if (CosmosUtility.TryGetCosmosException(ex, out CosmosException ce) &&
                    (HttpStatusCode)ce.Status == HttpStatusCode.NotFound)
                {
                    if (cosmosContext.ResolvedAttribute.CreateIfNotExists)
                    {
                        create = true;
                    }
                    else
                    {
                        // Throw a custom error so that it's easier to decipher.
                        string message = $"The container '{cosmosContext.ResolvedAttribute.ContainerName}' (in database '{cosmosContext.ResolvedAttribute.DatabaseName}') does not exist. To automatically create the collection, set '{nameof(CosmosAttribute.CreateIfNotExists)}' to 'true'.";
                        throw new InvalidOperationException(message, ex);
                    }
                }
                else
                {
                    throw;
                }
            }

            if (create)
            {
                await CosmosUtility.CreateDatabaseAndContainerNameIfNotExistAsync(cosmosContext);

                await UpsertDocument(cosmosContext, item);
            }
        }