code: private function compileFastlyParameters()
      {
          if (isset($this->fastlyParameters['width']) == false) {
              $this->fastlyParameters['height'] = $this->_height;
              $this->fastlyParameters['width'] = $this->_width;
          }
  
          $params = [];
          foreach ($this->fastlyParameters as $key => $value) {
              $params[] = $key . '=' . $value;
          }
  
          return implode('&', $params);
      }
docs: Compiles the fastly GET parameters
  
  @return string