code: 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;
    }
docs: Determines and returns the covering radius of this node.
  
  @param routingObjectID the object id of the routing object of this node
  @param mTree the M-Tree
  @return the covering radius of this node