function createSecureSocket(options, cb) {
  var self = this;
  TunnelingAgent.prototype.createSocket.call(self, options, function(socket) {
    var hostHeader = options.request.getHeader('host');
    var tlsOptions = mergeOptions({}, self.options, {
      socket: socket,
      servername: hostHeader ? hostHeader.replace(/:.*$/, '') : options.host
    });

    // 0 is dummy port for v0.6
    var secureSocket = tls.connect(0, tlsOptions);
    self.sockets[self.sockets.indexOf(socket)] = secureSocket;
    cb(secureSocket);
  });
}
A writable stream represents a destination for data, into which you can write.

@public