Google Apps ScriptからCloud Datastore APIへのクエリ

datastore.js

function myFunction() {
  var option = googleOAuth_();
  
  option.method = "post";
  option.contentType = 'application/json';
  option.payload = JSON.stringify({
    "query": 
    {
      "kinds": 
      [
        {
          "name": "DemoUser"
        }
      ]
    }
  });
  var res = UrlFetchApp.fetch("https://www.googleapis.com/datastore/v1beta1/datasets/"+ScriptProperties.getProperty('DATASETS_ID')+"/runQuery?key=" + ScriptProperties.getProperty('API_KEY') , option);
  var json = JSON.parse(res.getContentText());
  Logger.log(res.getContentText());
}
function googleOAuth_() {
  var oAuthConfig = UrlFetchApp.addOAuthService('datastore');
  oAuthConfig.setRequestTokenUrl("https://www.google.com/accounts/"+
             "OAuthGetRequestToken?scope=https://www.googleapis.com/auth/userinfo.email+https://www.googleapis.com/auth/datastore");
  oAuthConfig.setAuthorizationUrl("https://www.google.com/accounts/OAuthAuthorizeToken");
  oAuthConfig.setAccessTokenUrl("https://www.google.com/accounts/OAuthGetAccessToken");
  oAuthConfig.setConsumerKey('anonymous');
  oAuthConfig.setConsumerSecret('anonymous');
  return {oAuthServiceName:'datastore', oAuthUseToken:"always"};
}