BaseWicketTester discards cookies with MaxAge = -1 when processing a new request

BaseWicketTesters' method processRequest only copies cookies with maxAge > 0 to the new request, discarding cookies with maxAge = -1. However http://docs.oracle.com/javaee/1.4/api/javax/servlet/http/Cookie.html#getMaxAge%28%29 states that cookies with maxAge = -1 are session cookies, and should be deleted when the browser is closed, not when a new request is handled.