* @param errorStream the PrintStream to which backtrace should be printed
*/
public void printBacktrace(PrintStream errorStream, int skip) {
IRubyObject backtrace = callMethod(getRuntime().getCurrentContext(), "backtrace");
if (!backtrace.isNil() && backtrace instanceof RubyArray) {
IRubyObject[] elements = backtrace.convertToArray().toJavaArray();
for (int i = skip; i < elements.length; i++) {
IRubyObject stackTraceLine = elements[i];
if (stackTraceLine instanceof RubyString) {
printStackTraceLine(errorStream, stackTraceLine);