doc:   [
    DocGroup({"tag": "pre"}, [
        DocChars("1 ")
    ]),
    DocGroup({"tag": "h2"}, [
        DocChars("lSw"), DocGroup({"client": "left", "tag": "caret"}, []),
        DocChars(" 3RTY3Y6 m 0rOuw13lDC Nv ok2det25c 7t 5")
    ]),
    DocGroup({"tag": "p"}, [
        DocChars("H3i8"), DocGroup({"tag": "caret", "client": "right"}, []),
        DocChars("g 75Q0 PN mv HqyHb rEjSJL3skS  2 j1 s6 X   J3H  cCv b35 AhS 3 h2xj8747pdJkL 4F   7y  kNHello world58r8 kI0O6P nnHv 2 5  R A w fBBE at's up with you?")
    ])
]

a_del: [
    DelWithGroup([
        DelSkip(2)
    ]),
    DelWithGroup([
        DelSkip(2), DelChars(1), DelGroup([]),
        DelSkip(39)
    ]),
    DelWithGroup([])
]
a_add: [
    AddWithGroup([
        AddSkip(2)
    ]),
    AddWithGroup([
        AddSkip(41)
    ]),
    AddWithGroup([
        AddChars("l"), AddGroup({"tag": "caret", "client": "left"}, [])
    ])
]

b_del: [
    DelWithGroup([
        DelSkip(2)
    ]),
    DelWithGroup([
        DelSkip(3), DelWithGroup([]),
        DelSkip(39)
    ]),
    DelGroup([
        DelSkip(153)
    ])
]
b_add: [
    AddWithGroup([
        AddSkip(2)
    ]),
    AddWithGroup([
        AddSkip(3), AddWithGroup([]),
        AddSkip(39)
    ]),
    AddGroup({"tag": "p"}, [
        AddSkip(153)
    ])
]