.addQueryParameter("redirect_uri", redirectUrl.toString())
        .build();
    Request request = new Request.Builder()
        .url(url)
        .build();
    Call call = httpClient.newCall(request);
    try (Response response = call.execute()) {
      JsonAdapter<OAuthSession> jsonAdapter = moshi.adapter(OAuthSession.class);
      return jsonAdapter.fromJson(response.body().source());
    }
  }