
doc:   [
    DocGroup({"tag": "bullet"}, [
        DocGroup({"tag": "p"}, [
            DocChars("m  "), DocGroup({"client": "a", "tag": "caret"}, [])
        ]),
        DocGroup({"tag": "p"}, [
            DocChars("s"), DocGroup({"client": "c", "tag": "caret"}, []),
            DocChars("4"), DocGroup({"tag": "caret", "client": "b"}, []),
            DocChars("  7 wrbtoywl   w50X1 up with you?")
        ])
    ])
]

a_del: [
    DelWithGroup([
        DelWithGroup([
            DelSkip(1), DelChars(2), DelGroup([])
        ])
    ])
]
a_add: [
    AddWithGroup([
        AddWithGroup([
            AddSkip(1), AddGroup({"client": "a", "tag": "caret"}, []),
            AddChars("j")
        ])
    ])
]

b_del: [
    DelGroup([
        DelWithGroup([
            DelSkip(3), DelWithGroup([])
        ]),
        DelWithGroup([
            DelSkip(1), DelWithGroup([]),
            DelSkip(1), DelGroup([])
        ])
    ])
]
b_add: [
    AddWithGroup([
        AddSkip(3), AddWithGroup([])
    ]),
    AddWithGroup([
        AddSkip(1), AddGroup({"client": "b", "tag": "caret"}, []),
        AddWithGroup([]),
        AddSkip(1)
    ])
]
