commandOutput not being executed

[IandroidFan]

public Boolean getState(int number) {
        final String[] response = new String[1];
        Log.d("GET1", "num: "+number);
        Command getStateCmd = new Command(0, "cat /sys/devices/system/cpu/cpu" + number + "/online") {
            @Override
            public void commandOutput(int id, String line) {
                response[0] = line;
                Log.d("GET2", "line: "+line);
                super.commandOutput(id, line);
            }
            @Override
            public void commandCompleted(int id, int exitcode) {
                Log.d("GET2", "exitcode: " + exitcode);
                super.commandCompleted(id, exitcode);
            }
            @Override
            public void commandTerminated(int id, String reason) {
                Log.d("GET2", "reason: " + reason);
                super.commandTerminated(id, reason);
            }
        };
        try {
            RootTools.getShell(true).add(getStateCmd);
        }catch (IOException | RootDeniedException | TimeoutException ex) {
            ex.printStackTrace();
        }

        Log.d("GET3", "response: "+response[0]);

Logcat returns:

03-20 23:22:26.679 32757-32757/? D/GET1: num: 1
03-20 23:22:37.564 32757-32757/? D/GET3: response: null

It looks like that none of command* methods being executed.