private static async Task <ClientEntity> UpdateClientAsync(IBlobClient blobClient, string clientId, Func <ClientEntity, ClientEntity> updateFunc) { if (string.IsNullOrWhiteSpace(clientId)) { throw new ArgumentNullException(nameof(clientId)); } _ = blobClient ?? throw new ArgumentNullException(nameof(blobClient)); var container = blobClient.GetContainer(ClientContainer); ClientEntity entity = null; await container.UpdateItemAsync <ClientEntity>(clientId, (r) => { entity = null; var result = updateFunc(r.Item); entity = result; return(UpdateResult <ClientEntity> .Accept(result)); }); return(entity); }