def METHOD_NAME():
    # Make an indexed tree
    t = IndexedTree[MyDataType](MyDataType('root'), attrgetter('name'))
    t.add('root', MyDataType('a'))
    t.add('root', MyDataType('b'))
    # Make a simple separate tree segment
    n = Node[str](MyDataType('segment'))
    na = n.add(MyDataType('na'))
    n.add(MyDataType('nb'))
    na.add(MyDataType('naa'))
    # Shove it right in there
    t.insert_segment('b', n)
    assert 'segment' in t
    assert 'naa' in t
    assert repr(t['naa']) == "Node(MyDataType('naa'))"
    assert repr(t['b'].nodes) == "[Node(MyDataType('segment'))]"
    assert repr(t['segment'].nodes) == "[Node(MyDataType('na')), Node(MyDataType('nb'))]"
    assert repr(t['na'].nodes) == "[Node(MyDataType('naa'))]"
    # Ensure parent chain extends into segment completely
    assert t['naa'].parent is t['na']
    assert t['segment'].parent is t['b']