protected void stratStep(int numFolds){
  ArrayList<Instance> newVec=new ArrayList<Instance>(m_Instances.size());
  int start=0, j;
  while (newVec.size() < numInstances()) {
    j=start;
    while (j < numInstances()) {
      newVec.add(instance(j));
      j=j + numFolds;
    }
    start++;
  }
  m_Instances=newVec;
}

protected void stratStep ( int numFolds ) { ArrayList < Instance > newVec = new ArrayList < Instance > ( m_Instances . size ( ) ) ; int start = 0 , j ; while ( newVec . size ( ) < numInstances ( ) ) { j = start ; while ( j < numInstances ( ) ) { newVec . add ( instance ( j ) ) ; j = j + numFolds ; } start ++ ; } m_Instances = newVec ; }
help function needed for stratification of set .
