
doc:   [
    DocGroup({"tag": "bullet"}, [
        DocGroup({"tag": "h1"}, [
            DocGroup({"client": "b", "tag": "caret"}, [])
        ]),
        DocGroup({"tag": "p"}, [
            DocChars("6B"), DocGroup({"tag": "caret", "client": "a"}, []),
            DocChars(" 6sN  hIllo world!j 7W t\'s up with you?")
        ])
    ])
]

a_del: [
    DelGroup([
        DelWithGroup([
            DelWithGroup([])
        ]),
        DelWithGroup([
            DelSkip(1), DelChars(1), DelGroup([])
        ])
    ])
]
a_add: [
    AddWithGroup([
        AddGroup({"tag": "caret", "client": "a"}, []),
        AddWithGroup([])
    ]),
    AddWithGroup([
        AddSkip(1)
    ])
]

b_del: [
    DelWithGroup([
        DelWithGroup([])
    ])
]
b_add: [
    AddWithGroup([
        AddWithGroup([
            AddChars("I")
        ])
    ])
]
