login method
Returns the token or throws an error
Implementation
Future<String> login(String email, String password) async {
try {
final request = LoginRequest()
..email = email
..password = password;
final response = await _stub.login(request);
if (response.success) {
return response.token;
}
final err = ('Login failed: ${response.message}');
throw err;
} catch (e) {
final err = ('Error during login: $e');
throw err;
}
}