code: func (v *validatorRule) Claim(r *http.Request) bool {
  	// check for pre-cache validators, if at least one of them return false
  	// for this specific request, then skip the whole cache
  	for _, shouldProcess := range v.preValidators {
  		if !shouldProcess(r) {
  			return false
  		}
  	}
  	return true
  }
docs: // Claim returns true if incoming request can claim for a cached handler
  // the original handler should run as it is and exit