helper func
helper func

onekiloparsec/SwiftAA,alex-vasenin/SwiftAA,onekiloparsec/SwiftAA,alex-vasenin/SwiftAA,onekiloparsec/SwiftAA,alex-vasenin/SwiftAA,onekiloparsec/SwiftAA,alex-vasenin/SwiftAA,onekiloparsec/SwiftAA,alex-vasenin/SwiftAA