docs: public List<String> getDataSets(String... groups) {
          synchronized (Hdf5Archive.LOCK_OBJECT) {
              if (groups.length == 0)
                  return getObjects(this.file, H5O_TYPE_DATASET);
              Group[] groupArray = openGroups(groups);
              List<String> ls = getObjects(groupArray[groupArray.length - 1], H5O_TYPE_DATASET);
              closeGroups(groupArray);
              return ls;
          }
      }