@Override
    public long getLastActiveMillis() {
        return mSharedPreferences.getLong(LAST_ACTIVE_MILLIS_PREFERENCE_KEY, 0);
    }
Static method that allows to get back the current static Instance of {@link AppLockImpl}

@param context       The current context of the {@link Activity}
@param activityClass The activity extending {@link AppLockActivity}
@return The instance.
lib/src/main/java/com/github/omadahealth/lollipin/lib/managers/AppLockImpl.java