nodeToSplit.m_SplitValue, nodeToSplit.m_SplitString,
nodeToSplit.m_SortedIndices, nodeToSplit.m_Weights, train);
// if split will generate node(s) which has total weights less than m_minNumObj,
// do not split
int attIndex = att.index();
if (subsetIndices[0][attIndex].length<minNumObj ||
subsetIndices[1][attIndex].length<minNumObj) {
nodeToSplit.makeLeaf(train);
BFTree nextNode = (BFTree)