public async Task <GrantedToken> GetTokenByResourceOwnerCredentialsGrantType(ResourceOwnerGrantTypeParameter resourceOwnerGrantTypeParameter, AuthenticationHeaderValue authenticationHeaderValue, X509Certificate2 certificate, string issuerName)
        {
            if (resourceOwnerGrantTypeParameter == null)
            {
                throw new ArgumentNullException(nameof(resourceOwnerGrantTypeParameter));
            }

            var processId = Guid.NewGuid().ToString();

            try
            {
                _eventPublisher.Publish(new GrantTokenViaResourceOwnerCredentialsReceived(Guid.NewGuid().ToString(), processId, _payloadSerializer.GetPayload(resourceOwnerGrantTypeParameter, authenticationHeaderValue), authenticationHeaderValue, 0));
                _oauthEventSource.StartGetTokenByResourceOwnerCredentials(resourceOwnerGrantTypeParameter.ClientId,
                                                                          resourceOwnerGrantTypeParameter.UserName,
                                                                          resourceOwnerGrantTypeParameter.Password);
                _resourceOwnerGrantTypeParameterValidator.Validate(resourceOwnerGrantTypeParameter);
                var result = await _getTokenByResourceOwnerCredentialsGrantType.Execute(resourceOwnerGrantTypeParameter,
                                                                                        authenticationHeaderValue, certificate, issuerName);

                var accessToken   = result != null ? result.AccessToken : string.Empty;
                var identityToken = result != null ? result.IdToken : string.Empty;
                _oauthEventSource.EndGetTokenByResourceOwnerCredentials(accessToken, identityToken);
                _eventPublisher.Publish(new TokenGranted(Guid.NewGuid().ToString(), processId, _payloadSerializer.GetPayload(result), 1));
                return(result);
            }
            catch (IdentityServerException ex)
            {
                _eventPublisher.Publish(new OAuthErrorReceived(Guid.NewGuid().ToString(), processId, ex.Code, ex.Message, 1));
                throw;
            }
        }