* @param exception An Exception thrown by JRuby
*/
private static void printException(Ruby runtime, Exception exception) {
assert exception != null;
if (exception instanceof RaiseException) {
JumpException je = (JumpException)exception;
if (je instanceof RaiseException) {
runtime.printError(((RaiseException)je).getException());
} else if (je instanceof JumpException.BreakJump) {
runtime.getErrorStream().println("break without block.");
} else if (je instanceof JumpException.ReturnJump) {