onChanged 
  fun onChanged(connectFlags: <Error class: unknown class> = ConnectFlags(0u), handler: (oldCookie: Cookie, newCookie: Cookie) -> Unit): <Error class: unknown class>(source)
Emitted when @jar changes.
If a cookie has been added,
Parameters
connectFlags 
a combination of ConnectFlags
handler
the Callback to connect. Params: oldCookie the old #SoupCookie value; newCookie the new #SoupCookie value