'''
You  are implementing a binary tree class from scratch which, in addition to insert, find, and delete, has a method getRandomNode() which returns a random node from the tree. All nodes should be equally likely to be chosen. Design and implement an algorithm for getRandomNode and explain how you would implement the rest of the methods.

Hints: 42, 54, 62, 75, 89, 99, 112, 119
'''


def rand_node(s):
    pass

if __name__ == '__main__':
    assert rand_node('') ==
    assert rand_node('') ==
    assert rand_node('') ==
    assert rand_node('') ==
    assert rand_node('') ==
