Trying a first version.

node_modules/undici/lib/websocket/symbols.js

@@ -0,0 +1,12 @@
+'use strict'
+
+module.exports = {
+  kWebSocketURL: Symbol('url'),
+  kReadyState: Symbol('ready state'),
+  kController: Symbol('controller'),
+  kResponse: Symbol('response'),
+  kBinaryType: Symbol('binary type'),
+  kSentClose: Symbol('sent close'),
+  kReceivedClose: Symbol('received close'),
+  kByteParser: Symbol('byte parser')
+}