_flexibleCollectionVC = FlexibleCollectionViewController(collectionViewLayout: CustomFlowLayout(), configuration: CollectionConfiguration(userInteractionEnabled: true, showsHorizontalScrollIndicator: false, isScrollEnabled: true, multipleTouchEnabled: false, backgroundColor: .clear))

_flexibleCollectionVC.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "UICollectionViewCell")
_flexibleCollectionVC.registerSupplementaryView(UIHeaderImageCollectionView.self, kind: .header, reuseIdentifier: UIHeaderImageCollectionView.reuseIdentifier)

_flexibleCollectionVC.requestCellIdentifier = { value in
  return "UICollectionViewCell"
}

_flexibleCollectionVC.requestSupplementaryIdentifier = { value in
  return UIHeaderImageCollectionView.reuseIdentifier
}

_flexibleCollectionVC.configureCell = { (cell: UICollectionViewCell, data: CollectionImageCellData?, indexPath: IndexPath) in
  guard let data = data else {
    return false
  }

  cell.backgroundColor = data.color

  return true
}

_flexibleCollectionVC.configureSupplementary = { (view: UICollectionReusableView, kind: SupplementaryKind, data: CollectionImageCellData?, indexPath: IndexPath) in
  if let view = view as? UIHeaderImageCollectionView, let data = data {
    view.text = data.category

    return true
  }

  return false
}

_flexibleCollectionVC.cellDidSelect = { value in
  return (deselect: true, animate: true)
}

_flexibleCollectionVC.estimateCellSize = { value in
  guard let layout = value.1 as? UICollectionViewFlowLayout else {
    return nil
  }

  let col: CGFloat = 3
  let width = value.0.bounds.width-(layout.sectionInset.left+layout.sectionInset.right)
  let side = round(width/col)-layout.minimumInteritemSpacing
  return CGSize(width: side, height: side)
}

_flexibleCollectionVC.setData(getData())

pod "FlexibleCollectionViewController"