For medium article - SOLID Swift Using Protocols !!!

SRPPass.swift

struct DataManager {
    
    let dataLoader: DataDownloader
    let dataParser: DataParser
    let dbManager: DBManager
    
    init(dataLoader: DataDownloader, dataParser: DataParser, dbManager: DBManager) {
        self.dataLoader = dataLoader
        self.dataParser = dataParser
        self.dbManager = dbManager
    }
    
    func manage() {
        let data = dataLoader.loadData()
        let array = dataParser.parseData(data)
        dbManager.saveData(array)
    }
}

struct DataDownloader {
    func loadData() -> Data { }
}

struct DataParser {
    func parseData(_: Data) -> [String] { }
}

struct DBManager {
    func saveData(_: [String]) { }
}