# vim: set fileencoding=utf-8 :

class Node(object):
    def __init__(self, label, *nodes):
        self.label, self.nodes = label, nodes

    def __getitem__(self, n):
        return self.nodes[n]

    def __setitem__(self, n, node):
        self.nodes[n] = node

    def __iter__(self):
        return iter(self.nodes)

    def __len__(self):
        return len(self.nodes)

    def title(self):
        return str(self.label)


class Leaf(object):
    def __init__(self, label):
        self.label = label

    def title(self):
        return str(self.label)