code: function setAuthType(auth_type) {
      var headers = {
          'Content-Type': 'application/json',
          'Accept': 'application/json'
      };
  
      if (auth_type == 'AccessToken') {
          headers['Authorization'] = _config.access_token;
      }
      else if (auth_type == 'AppCredentials') {
          headers['x-accela-appid'] = _config.app_id
          headers['x-accela-appsecret'] = _config.app_secret;
      }
      else {
          headers['x-accela-appid'] = _config.app_id
          headers['x-accela-agency'] = _config.agency;
          headers['x-accela-environment'] = _config.environment;
      }
      return headers;
  }
docs: Method to set authorization type.