public async void Delete_External_ValidateIsGone()
        {
            const string objectName = "Account";
            const string fieldName  = "ExternalId__c";
            var          fieldId    = "123" + DateTime.Now.Ticks;

            await CreateExternalIdField(objectName, fieldName);

            var account = new Account {
                Name = "Upserted To Delete", Description = "Upserted Account Description to Delete"
            };
            var success = await _client.UpsertExternalAsync(objectName, fieldName, fieldId, account);

            var resultExists = await _client.QueryByIdAsync <Account>("Account", success.Id);

            Assert.IsNotNull(resultExists);

            await _client.DeleteExternalAsync("Account", fieldName, fieldId);

            var resultDoesNotExists = await _client.QueryByIdAsync <Account>("Account", success.Id);

            Assert.IsNull(resultDoesNotExists);
        }