Add support for a WebSocket extension of the given @extension_type.
When a WebSocket client requests an extension of @extension_type,
a new #SoupWebsocketExtension of type @extension_type will be created
to handle the request.
You can also add support for a WebSocket extension to the server at
construct time by using the %SOUP_SERVER_ADD_WEBSOCKET_EXTENSION property.
Note that #SoupWebsocketExtensionDeflate is supported by default, use
soup_server_remove_websocket_extension() if you want to disable it.
Add support for a WebSocket extension of the given @extension_type. When a WebSocket client requests an extension of @extension_type, a new #SoupWebsocketExtension of type @extension_type will be created to handle the request.
You can also add support for a WebSocket extension to the server at construct time by using the %SOUP_SERVER_ADD_WEBSOCKET_EXTENSION property. Note that #SoupWebsocketExtensionDeflate is supported by default, use soup_server_remove_websocket_extension() if you want to disable it.