code: func (c *BundlingChecker) contains(items []checkerItem) ([]*isolatedclient.PushState, error) {
  	var digests []*service.HandlersEndpointsV1Digest
  	for _, item := range items {
  		digests = append(digests, &service.HandlersEndpointsV1Digest{
  			Digest:     string(item.item.Digest),
  			Size:       item.item.Size,
  			IsIsolated: item.isolated,
  		})
  	}
  	pushStates, err := c.svc.Contains(c.ctx, digests)
  	if err != nil {
  		return nil, fmt.Errorf("isolate Contains call failed: %v", err)
  	}
  	return pushStates, nil
  }
docs: // contains calls isolateService.Contains on the supplied checkerItems.