String alias = args[1];                                // which alias to check

        int fieldNo = Integer.parseInt(args[2]);            // which field to check for nulls

       

        Map<String, ClassWithArgs> monitorClasses = new HashMap<String, ClassWithArgs>();

        monitorClasses.put(alias, new ClassWithArgs(RIMonitorAgent.class, fieldNo));

        parsedPigScript.trace(RICoordinator.class, monitorClasses);

    }

        String testAlias = args[1];                                // which alias is being tested

        double sampleRate = Double.parseDouble(args[2]);        // what fraction of data to sample for testing

        String goldenLogicClass = args[3];                        // class that gives the "golden" (correct) output for a given input tuple

        List<String> upstreamAliases = parsedPigScript.inEdges(testAlias);

        if (upstreamAliases.size() != 1) throw new IllegalArgumentException("Unable to perform testing of given alias.");

        String prevAlias = upstreamAliases.iterator().next();

       

        String pigScriptFilename = args[0];

        ParsedPigScript parsedPigScript = pennyServer.parse(pigScriptFilename);

        Map<String, ClassWithArgs> monitorClasses = new HashMap<String, ClassWithArgs>();

            // only put agents at the beginning of each task pipeline

            // (can't differentiate which step in pipeline is causing delay -- can only tell if a tuple coming into the pipeline is taking longer to go through the pipeline than other tuples)

            if (parsedPigScript.isTaskEntryPoint(alias)) {

                monitorClasses.put(alias, new ClassWithArgs(LAMonitorAgent.class));

            }

        String traceAlias = args[1];                            // script alias of tuple to get trace of

        String traceTuple = args[2];                            // tuple to trace (has to match exactly tuple.toSTring())

    // Ibis change : start

    // Ibis change : end

   

        Map<String, ClassWithArgs> monitorClasses = new HashMap<String, ClassWithArgs>();

        for (String alias : parsedPigScript.aliases()) {

      // Ibis change : start

        if (!(parsedPigScript.aliases().contains(traceAlias) && parsedPigScript.operator(traceAlias).equals("LOLoad"))) throw new IllegalArgumentException("Invalid alias.");

    // Ibis change : end

   

        Map<String, ClassWithArgs> monitorClasses = new HashMap<String, ClassWithArgs>();

      // Ibis change : start

            if (parsedPigScript.operator(alias).equals("LOLoad")) {

      // Ibis change : end

                monitorClasses.put(alias, new ClassWithArgs(BTInjectTaintMonitorAgent.class));                   

            } else if (alias.equals(traceAlias)) {