// URL Escaped from string
extension String {
    var URLEscaped: String {
       return self.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed) ?? ""
    }
}


// check if string has only alpha numeric characters
if username.rangeOfCharacter(from: CharacterSet.alphanumerics.inverted) != nil {
    return .just(.failed(message: "Username can only contain numbers or digits"))
}