public int onBreak(Frame frame) {
        linesEncountered.add(frame.getLineNumber());

        System.out.println("Breakpoint Encountered [source:" + frame.getSourceName() + "; line:" + frame.getLineNumber() + "]");
        System.out.println("vars:" + frame.getFactory().getKnownVariables());
        System.out.println("Resume Execution");
        return 0;
      }