以下异常：
SocketIOException: Unexpected handshake error in client (OS Error: errno = -12268)
#0 _SecureFilterImpl.handshake (dart:io-patch:849:8)
#1 _SecureSocket._secureHandshake (dart:io:7382:28)
#2 _SecureSocket._secureConnectHandler._secureConnectHandler (dart:io:7294:21)
#3 _Socket._updateOutHandler.firstWriteHandler (dart:io-patch:773:64)
#4 _SocketBase._multiplex (dart:io-patch:408:26)
#5 _SocketBase._sendToEventHandler.<anonymous closure> (dart:io-patch:509:20)
#6 _ReceivePortImpl._handleMessage (dart:isolate-patch:37:92)
以下代码的结果：
SocketIOException: Unexpected handshake error in client (OS Error: errno = -12268)
#0 _SecureFilterImpl.handshake (dart:io-patch:849:8)
#1 _SecureSocket._secureHandshake (dart:io:7382:28)
#2 _SecureSocket._secureConnectHandler._secureConnectHandler (dart:io:7294:21)
#3 _Socket._updateOutHandler.firstWriteHandler (dart:io-patch:773:64)
#4 _SocketBase._multiplex (dart:io-patch:408:26)
#5 _SocketBase._sendToEventHandler.<anonymous closure> (dart:io-patch:509:20)
#6 _ReceivePortImpl._handleMessage (dart:isolate-patch:37:92)
请注意，如果我将 url 替换为“http”而不是“https”，它将按预期工作。