Can I use 'union' to separate the path into inner and outer rings?

[BigZebra101010]

there are inner and outer rings in boost::geometry::polygon, Can I use 'union' to separate the path into inner and outer rings?

here is the sample code:

void TestMerge()
{
    Paths64 subject;

    Clipper2Lib::Paths64 solution;
    SvgWriter svg;
    Clipper64 c;
    c.PreserveCollinear = false;

    subject.push_back(MakePath({ 902002,160176 , 902134,160176 , 902134,160684 , 903078,160684 , 903078,160196 , 903210,160196 , 903210,160684 , 903794,160684 , 903794,160196 , 903926,160196 , 903926,160684 , 904510,160684 , 904510,160196 , 904642,160196 , 904642,160684 , 905226,160684 , 905226,160196 , 905358,160196 , 905358,160684 , 905942,160684 , 905942,160196 , 906074,160196 , 906074,160684 , 906658,160684 , 906658,160196 , 906790,160196 , 906790,160684 , 907374,160684 , 907374,160196 , 907506,160196 , 907506,160684 , 908090,160684 , 908090,160196 , 908222,160196 , 908222,160684 , 908806,160684 , 908806,160196 , 908938,160196 , 908938,160684 , 910162,160684 , 910162,164468 , 908938,164468 , 908938,164956 , 908806,164956 , 908806,164468 , 908222,164468 , 908222,164956 , 908090,164956 , 908090,164468 , 907506,164468 , 907506,164956 , 907374,164956 , 907374,164468 , 906790,164468 , 906790,164956 , 906658,164956 , 906658,164468 , 906074,164468 , 906074,164956 , 905942,164956 , 905942,164468 , 905358,164468 , 905358,164956 , 905226,164956 , 905226,164468 , 904642,164468 , 904642,164956 , 904510,164956 , 904510,164468 , 903926,164468 , 903926,164956 , 903794,164956 , 903794,164468 , 903210,164468 , 903210,164956 , 903078,164956 , 903078,164468 , 902134,164468 , 902134,166252 , 903078,166252 , 903078,165764 , 903210,165764 , 903210,166252 , 903794,166252 , 903794,165764 , 903926,165764 , 903926,166252 , 904510,166252 , 904510,165764 , 904642,165764 , 904642,166252 , 905226,166252 , 905226,165764 , 905358,165764 , 905358,166252 , 905942,166252 , 905942,165764 , 906074,165764 , 906074,166252 , 906658,166252 , 906658,165764 , 906790,165764 , 906790,166252 , 907374,166252 , 907374,165764 , 907506,165764 , 907506,166252 , 908090,166252 , 908090,165764 , 908222,165764 , 908222,166252 , 908806,166252 , 908806,165764 , 908938,165764 , 908938,166252 , 910162,166252 , 910162,164468 , 910162,160684 , 910162,160684 , 910162,161684 , 908938,161684 , 908938,162140 , 908806,162140 , 908806,161684 , 908222,161684 , 908222,162140 , 908090,162140 , 908090,161684 , 907506,161684 , 907506,162140 , 907374,162140 , 907374,161684 , 906790,161684 , 906790,162140 , 906658,162140 , 906658,161684 , 906074,161684 , 906074,162140 , 905942,162140 , 905942,161684 , 905358,161684 , 905358,162140 , 905226,162140 , 905226,161684 , 904642,161684 , 904642,162140 , 904510,162140 , 904510,161684 , 903926,161684 , 903926,162140 , 903794,162140 , 903794,161684 , 903210,161684 , 903210,162140 , 903078,162140 , 903078,161684 , 902134,161684 , 902134,163468 , 903078,163468 , 903078,163012 , 903210,163012 , 903210,163468 , 903794,163468 , 903794,163012 , 903926,163012 , 903926,163468 , 904510,163468 , 904510,163012 , 904642,163012 , 904642,163468 , 905226,163468 , 905226,163012 , 905358,163012 , 905358,163468 , 905942,163468 , 905942,163012 , 906074,163012 , 906074,163468 , 906658,163468 , 906658,163012 , 906790,163012 , 906790,163468 , 907374,163468 , 907374,163012 , 907506,163012 , 907506,163468 , 908090,163468 , 908090,163012 , 908222,163012 , 908222,163468 , 908806,163468 , 908806,163012 , 908938,163012 , 908938,163468 , 910162,163468 , 910162,161684 , 910162,160684 , 910162,160684 , 910162,160176 , 910294,160176 , 910294,160684 , 910294,163468 , 910294,166252 , 910294,169036 , 910294,171820 , 910294,174604 , 910294,175604 , 910162,175604 , 910162,174604 , 910162,172820 , 908938,172820 , 908938,173276 , 908806,173276 , 908806,172820 , 908222,172820 , 908222,173276 , 908090,173276 , 908090,172820 , 907506,172820 , 907506,173276 , 907374,173276 , 907374,172820 , 906790,172820 , 906790,173276 , 906658,173276 , 906658,172820 , 906074,172820 , 906074,173276 , 905942,173276 , 905942,172820 , 905358,172820 , 905358,173276 , 905226,173276 , 905226,172820 , 904642,172820 , 904642,173276 , 904510,173276 , 904510,172820 , 903926,172820 , 903926,173276 , 903794,173276 , 903794,172820 , 903210,172820 , 903210,173276 , 903078,173276 , 903078,172820 , 902134,172820 , 902134,174604 , 903078,174604 , 903078,174148 , 903210,174148 , 903210,174604 , 903794,174604 , 903794,174148 , 903926,174148 , 903926,174604 , 904510,174604 , 904510,174148 , 904642,174148 , 904642,174604 , 905226,174604 , 905226,174148 , 905358,174148 , 905358,174604 , 905942,174604 , 905942,174148 , 906074,174148 , 906074,174604 , 906658,174604 , 906658,174148 , 906790,174148 , 906790,174604 , 907374,174604 , 907374,174148 , 907506,174148 , 907506,174604 , 908090,174604 , 908090,174148 , 908222,174148 , 908222,174604 , 908806,174604 , 908806,174148 , 908938,174148 , 908938,174604 , 910162,174604 , 910162,175604 , 910162,175604 , 910162,171820 , 910162,170036 , 908938,170036 , 908938,170524 , 908806,170524 , 908806,170036 , 908222,170036 , 908222,170524 , 908090,170524 , 908090,170036 , 907506,170036 , 907506,170524 , 907374,170524 , 907374,170036 , 906790,170036 , 906790,170524 , 906658,170524 , 906658,170036 , 906074,170036 , 906074,170524 , 905942,170524 , 905942,170036 , 905358,170036 , 905358,170524 , 905226,170524 , 905226,170036 , 904642,170036 , 904642,170524 , 904510,170524 , 904510,170036 , 903926,170036 , 903926,170524 , 903794,170524 , 903794,170036 , 903210,170036 , 903210,170524 , 903078,170524 , 903078,170036 , 902134,170036 , 902134,171820 , 903078,171820 , 903078,171332 , 903210,171332 , 903210,171820 , 903794,171820 , 903794,171332 , 903926,171332 , 903926,171820 , 904510,171820 , 904510,171332 , 904642,171332 , 904642,171820 , 905226,171820 , 905226,171332 , 905358,171332 , 905358,171820 , 905942,171820 , 905942,171332 , 906074,171332 , 906074,171820 , 906658,171820 , 906658,171332 , 906790,171332 , 906790,171820 , 907374,171820 , 907374,171332 , 907506,171332 , 907506,171820 , 908090,171820 , 908090,171332 , 908222,171332 , 908222,171820 , 908806,171820 , 908806,171332 , 908938,171332 , 908938,171820 , 910162,171820 , 910162,175604 , 910162,175604 , 910162,169036 , 910162,167252 , 908938,167252 , 908938,167708 , 908806,167708 , 908806,167252 , 908222,167252 , 908222,167708 , 908090,167708 , 908090,167252 , 907506,167252 , 907506,167708 , 907374,167708 , 907374,167252 , 906790,167252 , 906790,167708 , 906658,167708 , 906658,167252 , 906074,167252 , 906074,167708 , 905942,167708 , 905942,167252 , 905358,167252 , 905358,167708 , 905226,167708 , 905226,167252 , 904642,167252 , 904642,167708 , 904510,167708 , 904510,167252 , 903926,167252 , 903926,167708 , 903794,167708 , 903794,167252 , 903210,167252 , 903210,167708 , 903078,167708 , 903078,167252 , 902134,167252 , 902134,169036 , 903078,169036 , 903078,168580 , 903210,168580 , 903210,169036 , 903794,169036 , 903794,168580 , 903926,168580 , 903926,169036 , 904510,169036 , 904510,168580 , 904642,168580 , 904642,169036 , 905226,169036 , 905226,168580 , 905358,168580 , 905358,169036 , 905942,169036 , 905942,168580 , 906074,168580 , 906074,169036 , 906658,169036 , 906658,168580 , 906790,168580 , 906790,169036 , 907374,169036 , 907374,168580 , 907506,168580 , 907506,169036 , 908090,169036 , 908090,168580 , 908222,168580 , 908222,169036 , 908806,169036 , 908806,168580 , 908938,168580 , 908938,169036 , 910162,169036 , 910162,175604 , 903210,175604 , 903210,176092 , 903078,176092 , 903078,175604 , 902134,175604 , 902134,177388 , 902002,177388 , 902002,160176 }));

    c.Execute(ClipType::Union, FillRule::NonZero, solution);

    std::cout << "solution size: " << solution2.size() << std::endl;

    SvgAddSubject(svg, subject, FillRule::NonZero);
    SvgAddSolution(svg, solution, FillRule::NonZero, false);
    std::string filename = "my_poly.svg";
    SvgSaveToFile(svg, filename, 3000, 1000, 10);
    System(filename);
}

the subject is

the solution is

I don't know if this is a bug.
Is there a way to remove the line.