docs: private double distance(Instance inst1, Instance inst2)
  	{
  		double dist = 0.0;
  		
  		for(int i = 0 ; i < inst1.numAttributes() ; i++)
  		{
  			dist += Math.pow((inst1.value(i) - inst2.value(i)), 2.0);
  		}
  		
  		return Math.sqrt(dist);
  	}