def __init__(self, root):
        self.stk = []
        self.cur = root
Like the |Stat abut command.  It concatenates two arrays column-wise
dataset/ETHPy150Open algorhythms/LintCode/Implement Iterator of Binary Search Tree.py/Solution.__init__--crossover with--dataset/ETHPy150Open sunlightlabs/clearspending/completeness/statlib/pstat.py/aabut