code: private List<String> getObjects(Group fileGroup, int objType) {
          synchronized (Hdf5Archive.LOCK_OBJECT) {
              List<String> groups = new ArrayList<>();
              for (int i = 0; i < fileGroup.getNumObjs(); i++) {
                  BytePointer objPtr = fileGroup.getObjnameByIdx(i);
                  if (fileGroup.childObjType(objPtr) == objType)
                      groups.add(fileGroup.getObjnameByIdx(i).getString());
              }
              return groups;
          }
      }
docs: Get list of objects with a given type from a file group.
  
  @param fileGroup HDF5 file or group
  @param objType   Type of object as integer
  @return List of HDF5 group objects