docs: public double coveringRadiusFromEntries(DBID routingObjectID, AbstractMTree<O, N, E, ?> mTree) {
      double coveringRadius = 0.;
      for(int i = 0; i < getNumEntries(); i++) {
        E entry = getEntry(i);
        final double cover = entry.getParentDistance() + entry.getCoveringRadius();
        coveringRadius = coveringRadius < cover ? cover : coveringRadius;
      }
      return coveringRadius;
    }