class ColumnIterator implements Iterator<String> {

	@Override
	public boolean hasNext() {
		if (_setIterator != null) {
			return _setIterator.hasNext();
		} else if (_listIterator != null) {
			return _listIterator.hasNext();
		} else {
			return false;
		}
	}

	@SuppressWarnings("unchecked") public  ColumnIterator(Collection<?> columnCollection);

}