def __init__(self, *args, **kwds):
        if len(args) > 1:
            raise TypeError('expected at most 1 arguments, got %d' % len(args))
        try:
            self.__root
        except AttributeError:
            self.__root = root = [None, None, None]     # sentinel node
            PREV = 0
            NEXT = 1
            root[PREV] = root[NEXT] = root
            self.__map = {}
        self.update(*args, **kwds)
Initialize an ordered dictionary.  Signature is the same as for
dataset/ETHPy150Open baseblack/ReproWeb/3rdParty/python/ordereddict.py/OrderedDict.__init__