login method
Implementation
Future<JwtToken> login(String username, String password) async {
try {
var jwtToken = await _jwtAuthApiClient.token(username, password);
_setToken(jwtToken);
return jwtToken;
} on DioException catch (e) {
var error = _handleError(e);
throw error;
} catch (e) {
rethrow;
}
}