                 self = .reconnectAfterBackingOff
             case 4200...4299:
                 self = .reconnectImmediately
-            case 4300...4399:
-                self = .reconnectIfAppropriate
             default:
                 self = .unknown
             }

        /// and that the client may reconnect immediately.
        case reconnectImmediately

        /// Indicates any other type of error in the connection being closed by Pusher Channels,
        /// and the client may reconnect if appropriate.
        case reconnectIfAppropriate

        /// Indicates that the reconnection strategy is unknown due to the closure code being
        /// outside of the expected range as specified by the Pusher Channels Protocol.
        case unknown

    /// and client does not support ping.
    case closedAfterInactivity                  = 4202

    // MARK: - Public properties

    var reconnectionStrategy: ReconnectionStrategy {
