code: private boolean findInclusiveNa(int colIdToFind) {
      if (parent == null) {
        return true;
      }
      else if (parent.getColId() == colIdToFind) {
        return inclusiveNa;
      }
      return parent.findInclusiveNa(colIdToFind);
    }
docs: Calculate whether the NA value for a particular colId can reach this node.
  @param colIdToFind Column id to find
  @return true if NA of colId reaches this node, false otherwise