public void OAuth_PostOAuthToken()
        {
            // ARRANGE
            string          clientId = "GS36SG653FD", clientSecret = "H7BD5D6G", grand = "pw", code = "ty";
            IRequestBuilder builder  = new DracoonRequestBuilder(FactoryClients.OAuthMock);
            RestRequest     expected = FactoryRestSharp.RestRequestWithoutAuth(OAuthConfig.OAuthPostAuthToken, Method.POST);

            expected.AddHeader("Authorization", "Basic " + Convert.ToBase64String(Encoding.UTF8.GetBytes(clientId + ":" + clientSecret)));
            expected.AddParameter("grant_type", grand, ParameterType.GetOrPost);
            expected.AddParameter("code", code, ParameterType.GetOrPost);

            // ACT
            IRestRequest actual = builder.PostOAuthToken(clientId, clientSecret, grand, code);

            // ASSERT
            Assert.Equal(expected, actual, new RestRequestComparer());
        }