code: public void addInstanceInfo(Instance ins) {
      if(m_Instances!=null)
        try{ update(ins); }
        catch(Exception ex) { ex.printStackTrace(); }
    }
docs: Adds the given instance info. This implementation updates the range
  datastructures of the DistanceFunction class.
  
  @param ins 	The instance to add the information of. Usually this is
  the test instance supplied to update the range of
  attributes in the  distance function.