CompositeStrategy.swift

class CompositeStrategy : Strategy {
  let wifiLoader: WifiLoader
  let cellularLoader: CellularLoader
  let localLoader: LocalLoader
  
  init(wifiLoader: WifiLoader, cellularLoader: CellularLoader, localLoader: LocalLoader){
    self.wifiLoader = wifiLoader
    self.cellularLoader = cellularLoader
    self.localLoader = localLoader
  }
  
  func load(completion: @escaping (Result<[FeedItem], Error>) {
     var loader: Loader?
     if Reachability.isWifi {
        loader = wifiLoader
     } else if Reachability.isCelluar {
        loader = cellularLoader
     } else if Reachability.isOffline {
        loader = localLoader
     }
    loader?.load(completion: completion)
    ...
  }
}