public string SignIn(string login, string password) { HttpConnector httpConnector = HttpConnector.GetInstance(); _tokenData = httpConnector.GetToken(login, password); string errorMessage = httpConnector.LastErrorMessage; if (errorMessage == null) { httpConnector.SetCredentials(_tokenData); _userRoles = httpConnector.GetCurrentRoles(); errorMessage = httpConnector.LastErrorMessage; } return(errorMessage); }