doc:   [
    DocGroup({"tag": "bullet"}, [
        DocGroup({"tag": "h1"}, [
            DocGroup({"client": "b", "tag": "caret"}, [])
        ]),
        DocGroup({"tag": "h3"}, [
            DocChars("6 P"), DocGroup({"client": "c", "tag": "caret"}, []),
            DocChars("o")
        ]),
        DocGroup({"tag": "h3"}, [
            DocChars("f"), DocGroup({"client": "d", "tag": "caret"}, [])
        ])
    ]),
    DocGroup({"tag": "h2"}, [
        DocChars("bU2aA2 e3 5WEtLs "), DocGroup({"client": "a", "tag": "caret"}, [])
    ]),
    DocGroup({"tag": "p"}, [
        DocChars(" 4C1")
    ]),
    DocGroup({"tag": "bullet"}, [
        DocGroup({"tag": "pre"}, [
            DocChars("8BP67  Og4uEG0  llo worlEst\'s up with you?")
        ])
    ])
]

a_del: [
    DelWithGroup([
        DelGroup([
            DelGroup([])
        ]),
        DelGroup([
            DelSkip(3), DelGroup([]),
            DelChars(1)
        ]),
        DelWithGroup([
            DelSkip(1), DelWithGroup([])
        ])
    ]),
    DelGroup([
        DelSkip(16), DelChars(1), DelGroup([])
    ]),
    DelGroup([
        DelSkip(4)
    ])
]
a_add: [
    AddWithGroup([
        AddGroup({"tag": "h1"}, [
            AddSkip(1), AddChars("C"), AddGroup({"tag": "caret", "client": "b"}, []),
            AddSkip(2)
        ]),
        AddGroup({"tag": "h3"}, [
            AddChars("D"), AddGroup({"tag": "caret", "client": "c"}, [])
        ]),
        AddWithGroup([
            AddSkip(1), AddWithGroup([])
        ])
    ]),
    AddGroup({"tag": "h2"}, [
        AddSkip(16), AddChars(" "), AddGroup({"client": "a", "tag": "caret"}, []),
        AddChars("o"), AddSkip(4)
    ])
]

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