public String getPeriodLogDescription() {
        if (periodLog == 0x00)
            return "Disabled";
        else if (periodLog == 0x01)
            return "1";
        else if (periodLog >= 0x02 && periodLog < 0x11) {
            final int lowerBound = (int) (Math.pow(2, periodLog - 1));
            final int upperBound = (int) (Math.pow(2, periodLog) - 1);
            return periodToTime(lowerBound) + " ... " + periodToTime(upperBound);
        } else if (periodLog == 0x11)
            return "65535";
        else return "Invalid";
    }
Returns true if the heartbeat subscriptions are enabled.
mesh/src/main/java/no/nordicsemi/android/mesh/utils/HeartbeatSubscription.java