code: public void readHardwareVersion(final Callback<String> callback) {
          gattClient.getDeviceProfile().getHardwareVersion(new DeviceProfile.VersionCallback() {
              @Override
              public void onComplete(String version) {
                  callback.onResult(version);
              }
          });
      }
docs: Read Bean firmware version
  
  @param callback the callback for the version string