private lazy var dataSource: EditMyPageDataSource = EditMyPageDataSource(
    configureCell: { [weak self] _, collectionView, indexPath, item in
      switch item {
      case let .name(name, placeholder):
        let cell = collectionView.dequeueReusableCell(for: indexPath) as FavorTextFieldCell
        cell.bind(placeholder: placeholder)
        cell.bind(text: name)
        return cell
      case let .id(name, placeholder):
        let cell = collectionView.dequeueReusableCell(for: indexPath) as FavorTextFieldCell
        cell.bind(placeholder: placeholder)
        cell.bind(text: name)
        return cell
      case let .favor(isSelected, favor):
        let cell = collectionView.dequeueReusableCell(for: indexPath) as EditMyPagePreferenceCell
        cell.isButtonSelected = isSelected
        cell.favor = favor
        return cell
      }
    }, configureSupplementaryView: { dataSource, collectionView, kind, indexPath in
      switch kind {
      case EditMyPageCollectionHeaderView.reuseIdentifier:
        let header = collectionView.dequeueReusableSupplementaryView(
          ofKind: kind,
          for: indexPath
        ) as EditMyPageCollectionHeaderView
        return header
      case UICollectionView.elementKindSectionHeader:
        let header = collectionView.dequeueReusableSupplementaryView(
          ofKind: kind,
          for: indexPath
        ) as FavorSectionHeaderView
        let headerTitle = dataSource[indexPath.section].header
        header.updateTitle(headerTitle)
        return header
      case UICollectionView.elementKindSectionFooter:
        let footer = collectionView.dequeueReusableSupplementaryView(
          ofKind: kind,
          for: indexPath
        ) as FavorSectionFooterView
        footer.footerDescription = dataSource[indexPath.section].footer
        return footer
      default:
        return UICollectionReusableView()
      }
    }
  )

  private lazy var dataSource: EditMyPageDataSource = EditMyPageDataSource(
    configureCell: { [weak self] _, collectionView, indexPath, item in
      switch item {
      case let .name(name, placeholder):
        let cell = collectionView.dequeueReusableCell(for: indexPath) as FavorTextFieldCell
        cell.bind(placeholder: placeholder)
        cell.bind(text: name)
        print(cell) // 🖐️ 여기
        return cell
      case let .id(name, placeholder):
        let cell = collectionView.dequeueReusableCell(for: indexPath) as FavorTextFieldCell
        cell.bind(placeholder: placeholder)
        cell.bind(text: name)
        print(cell) // 🖐️ 여기
        return cell
      case let .favor(isSelected, favor):
        let cell = collectionView.dequeueReusableCell(for: indexPath) as EditMyPagePreferenceCell
        cell.isButtonSelected = isSelected
        cell.favor = favor
        return cell
      }

open class RxCollectionViewSectionedReloadDataSource<Section: SectionModelType>
    : CollectionViewSectionedDataSource<Section>
    , RxCollectionViewDataSourceType {
    public typealias Element = [Section]

    open func collectionView(_ collectionView: UICollectionView, observedEvent: Event<Element>) {
        Binder(self) { dataSource, element in
            #if DEBUG
                dataSource._dataSourceBound = true
            #endif
            dataSource.setSections(element)
            collectionView.reloadData() // 👈 여기!
                    collectionView.collectionViewLayout.invalidateLayout()
        }.on(observedEvent)
    }
}

class FavorDataSource<Section: SectionModelType>: RxCollectionViewSectionedReloadDataSource<Section> {
  override func collectionView(_ collectionView: UICollectionView, observedEvent: Event<[Section]>) {
    Binder(self) { dataSource, element in
      dataSource.setSections(element)
      collectionView.reloadSections([2], animationStyle: .none) // 👈 테스트를 위해 고정적으로 2번째 섹션만 reload되도록
      collectionView.collectionViewLayout.invalidateLayout()
    }.on(observedEvent)
  }
}

public protocol SectionModelType: Hashable { }
public protocol SectionModelItem: Hashable { }

enum ProfileSectionItem: SectionModelItem {
  case profileSetupHelper(ProfileSetupHelperCellReactor)
  case preferences(ProfilePreferenceCellReactor)
  case anniversaries(ProfileAnniversaryCellReactor)
  case memo
  case friends(ProfileFriendCellReactor)
}

enum ProfileSection: SectionModelType {
  case profileSetupHelper
  case preferences
  case anniversaries
  case memo
  case friends
}

var sections: [ProfileSection] = []
var items: [[ProfileSectionItem]] = []

var profileSetupHelperItems: [ProfileSectionItem] = []
var preferencesItems: [ProfileSectionItem] = []
var anniversaryItems: [ProfileSectionItem] = []
var friendItems: [ProfileSectionItem] = []

func transform(state: Observable<State>) -> Observable<State> {
  return state.map { state in
    var newState = state
    var newSections: [ProfileSection] = []
    var newItems: [[ProfileSectionItem]] = []
    var profileSetupHelperItems: [ProfileSectionItem] = []

    // 취향
    if !state.preferencesItems.isEmpty {
	  newSections.append(.preferences)
	  newItems.append(state.preferencesItems)
    } else {
    profileSetupHelperItems.append(.profileSetupHelper(ProfileSetupHelperCellReactor(.preference)))
    }
    // 기념일
    if !state.anniversaryItems.isEmpty {
	  newSections.append(.anniversaries)
	  newItems.append(state.anniversaryItems)
    } else {
    profileSetupHelperItems.append(.profileSetupHelper(ProfileSetupHelperCellReactor(.anniversary)))
    }
    // 친구
    newSections.append(.friends)
    newItems.append(state.friendItems)
    // 새 프로필
    if !profileSetupHelperItems.isEmpty {
	  newSections.insert(.profileSetupHelper, at: .zero)
	  newItems.insert(profileSetupHelperItems, at: .zero)
    }
  
    newState.sections = newSections
    newState.items = newItems
    return newState
  }
}

reactor.state.map { (sections: $0.sections, items: $0.items) }
  .asDriver(onErrorRecover: { _ in return .empty()})
  .drive(with: self, onNext: { owner, sectionData in
	var snapshot: NSDiffableDataSourceSnapshot<ProfileSection, ProfileSectionItem> = .init()
	snapshot.appendSections(sectionData.sections)
	sectionData.items.enumerated().forEach { idx, items in
	  snapshot.appendItems(items, toSection: sectionData.sections[idx])
	}
	owner.dataSource.apply(snapshot, animatingDifferences: false)
  })
  .disposed(by: self.disposeBag)