docs: protected void correctlyInitialized() throws Exception {
      if(m_Instances==null)
        throw new Exception("No instances supplied.");
      else if(m_InstList==null) 
        throw new Exception("No instance list supplied.");
      else if(m_EuclideanDistance==null)
        throw new Exception("No Euclidean distance function supplied.");
      else if(m_Instances.numInstances() != m_InstList.length)
        throw new Exception("The supplied instance list doesn't seem to match " +
                            "the supplied instances");
    }