public async Task DeleteIfExists(string email) { if (string.IsNullOrWhiteSpace(email)) { throw new ArgumentException($"Parameter '{nameof(email)}' must have a value"); } var user = await _databaseClient.GetDocumentByExpression <UserModel>(_databaseName, _userCollectionName, u => u.Email == email); if (user != null) { await _databaseClient.DeleteDocument(_databaseName, _userCollectionName, user.Id); } }