def __init__(self, items=[]):
        self._items = [_DendrogramNode(item) for item in items]
        self._original_items = copy.copy(self._items)
        self._merge = 1
:param  items: the items at the leaves of the dendrogram
dataset/ETHPy150Open nltk/nltk/nltk/cluster/util.py/Dendrogram.__init__