code: private void merge(LinkedPair closestPair) {
  
  
  		int first = closestPair.getFirst();
  		int second = closestPair.getSecond();
  
  		for (int other=0;other<numItems;other++) {
  			matrix[Math.min(first,other)][Math.max(first, other)] = link(getDistance(first, other), getDistance(second, other));
  		}
  
  	}
docs: Merge 2 rows/columns of the matrix by the linkage function (see {@link #link(double, double)}
  @param closestPair