docs: private static double findMax(DistanceQuery<?> dq, DBIDIter i, DBIDs cy, double maxDist, double minMaxDist) {
      for(DBIDIter j = cy.iter(); j.valid(); j.advance()) {
        double dist = dq.distance(i, j);
        if(dist > maxDist) {
          // Stop early, if we already know a better candidate.
          if(dist >= minMaxDist) {
            return dist;
          }
          maxDist = dist;
        }
      }
      return maxDist;
    }