secure method
      
Future<SecureSocket> 
secure(
    
    
- dynamic host, {
- SecurityContext? context,
- bool onBadCertificate(- X509Certificate certificate
 
- void keyLog(- String line
 
- List<String> ? supportedProtocols,
inherited
    Implementation
Future<SecureSocket> secure(dynamic host, {
  SecurityContext? context,
  bool Function(X509Certificate certificate)? onBadCertificate,
  void Function(String line)? keyLog,
  List<String>? supportedProtocols,
  }) async {
  final secureSocket = await SecureSocket.secure(socket,
    host: host,
    context: context,
    onBadCertificate: onBadCertificate,
    keyLog: keyLog,
    supportedProtocols: supportedProtocols,
  );
  socket = secureSocket;
  _broadcast = socket.asBroadcastStream();
  return secureSocket;
}