doc:   [
    DocGroup({"tag": "h1"}, [
        DocChars("5j 5  1V11"), DocGroup({"client": "right", "tag": "caret"}, [])
    ]),
    DocGroup({"tag": "p"}, [
        DocChars("8ic ubC6 4f   L  N VYT 6e8 E  V3g  5r3wE lc bNP 1"), DocGroup({"tag": "caret", "client": "left"}, []),
        DocChars("lC71kOl36UW8   m465l1V 4L71y5arK8f  ao xy7rA Jko86t eW  y8w4KYK8R BR  8N6ExKeq 3s72 vwdsH8Q t 3  4 Ll S n8E3PWBi1XG2sH0 P S ello world! 5 W bWhat\'s up with you?")
    ])
]

a_del: [
    DelWithGroup([
        DelSkip(10), DelWithGroup([])
    ]),
    DelGroup([
        DelSkip(48), DelChars(1), DelGroup([]),
        DelSkip(160)
    ])
]
a_add: [
    AddWithGroup([
        AddSkip(10), AddWithGroup([])
    ]),
    AddGroup({"tag": "h2"}, [
        AddSkip(50), AddGroup({"tag": "caret", "client": "left"}, []),
        AddSkip(158)
    ])
]

b_del: [
    DelWithGroup([
        DelSkip(10), DelGroup([])
    ]),
    DelSkip(1)
]
b_add: [
    AddWithGroup([
        AddSkip(10)
    ]),
    AddWithGroup([
        AddGroup({"client": "right", "tag": "caret"}, [])
    ])
]