code: protected function constructRequestOptions($params)
      {
          //empty array
          $options = array();
  
          //add Bearer Token to the header
          $headers = array(
              'Authorization' => 'Bearer ' . $this->credentials->getBearerToken()
          );
  
          //if query parameters not supplied, continue.
          if(!is_null($params))
          {
              //Add query parameters to options.
              $options['query'] = $params;
          }
  
          //Add headers to the request.
          $options['headers'] = $headers;
  
          //return constructed options
          return $options;
      }
docs: Constructs an options array that is sent with the request.
  
  Uses Bearer Token since this is an AppConnection.
  
  @return array options for the request