code: function getService(privateKeyDetails) {
    return OAuth2.createService('PerfDash:' + Session.getActiveUser().getEmail())
        // Set the endpoint URL.
        .setTokenUrl('https://accounts.google.com/o/oauth2/token')
  
        // Set the private key and issuer.
        .setPrivateKey(privateKeyDetails['private_key'])
        .setIssuer(privateKeyDetails['client_email'])
  
        // Set the property store where authorized tokens should be persisted.
        .setPropertyStore(PropertiesService.getScriptProperties())
  
        // Set the scope. This must match one of the scopes configured during the
        // setup of domain-wide delegation.
        .setScope('https://www.googleapis.com/auth/userinfo.email');
  }
docs: Configures the service.
  @param {Object} privateKeyDetails Dict with private key and client email.