from __future__ import annotations
from typing import Any, Optional, Union


class _Node():
    """
    Node
    """
    _value: Optional[Any]


class BinaryTree():
    """
    BinaryTree
    
    Client Code
    -----------
    >>> bst = BinaryTree()
    >>> 
    """
    pass


if __name__ == '__main__':
    import doctest
    doctest.testmod()
