test7.in   1   0 begin      'aa'
test7.in   1   3 middle     'bbb'
test7.in   1   7 middle     'bb'
test7.in   1  10 middle     'bbbbb'
test7.in   1  16 middle     'b'
test7.in   1  18 end        'ccc'
test7.in   2   0 begin      'a'
test7.in   2   2 middle     'bb'
test7.in   2   5 middle     'bbb'
test7.in   2   9 middle     'b'
test7.in   2  11 end        'cc'
test7.in   3   0 middle     'bb'
test7.in   3   3 middle     'bbb'
test7.in   3   7 middle     'bbbbb'
test7.in   3  14 middle     'bb'
test7.in   3  17 middle     'bbb'
test7.in   4   0 everything 'ddddddddddddddd'
test7.in   5   0 begin      'aaa'
test7.in   5   4 middle     'bbb'
test7.in   5   8 middle     'bb'
test7.in   5  11 end        'cccc'
test7.in   8   0 None       ''