docs: function RelayrStrategy(options, verifyCallback) {
  
      if (!verifyCallback) { throw new TypeError('verify callback is required'); }
  
      options = options || {};
      options.authorizationURL = options.authorizationURL || 'https://api.relayr.io/oauth2/auth';
      options.responseType = options.responseType || 'token';
      options.tokenURL = 'https://api.relayr.io/oauth2/token';
      options.scope = 'access-own-user-info+configure-devices';
      options.scopeSeparator = options.scopeSeparator || ' ';
  
      OAuth2Strategy.call(this, options, verifyCallback);
      this.name = 'relayr';
      this._profileURL = options.profileURL || 'https://api.relayr.io/oauth2/user-info';
      this._appURL = options.appURL || 'https://api.relayr.io/oauth2/app-info';
      this._infocall = options.fetch || 'user';
      this._oauth2.useAuthorizationHeaderforGET(true);
  }