public String getPeriodLogDescription() {
        if (periodLog == 0x00)
            return "Disabled";
        else if (periodLog >= 0x01 || periodLog <= 0x11)
            return (int) Math.pow(2, periodLog - 1) + " s";
        else
            return "Prohibited";
    }
Returns true if the heartbeat subscriptions are enabled.
mesh/src/main/java/no/nordicsemi/android/mesh/utils/HeartbeatPublication.java