// Dump a traceback for exc to w
func (exc *ExceptionInfo) TracebackDump(w io.Writer) {
	if exc == nil {
		fmt.Fprintf(w, "Traceback <nil>\n")
		return
	}
	fmt.Fprintf(w, "Traceback (most recent call last):\n")
	exc.Traceback.TracebackDump(w)
	name := "<nil>"
	if exc.Type != nil {
		name = exc.Type.Name
	}
	fmt.Fprintf(w, "%v: %v\n", name, exc.Value)
}