docs: private OmemoCachedDeviceList deleteStaleDevices(OmemoDevice userDevice) {
          OmemoCachedDeviceList deviceList = getOmemoStoreBackend().loadCachedDeviceList(userDevice);
          int maxAgeHours = OmemoConfiguration.getDeleteStaleDevicesAfterHours();
          return removeStaleDevicesFromDeviceList(userDevice, userDevice.getJid(), deviceList, maxAgeHours);
      }