Questions about dwg_read_file() when POLYLINE_2D with flag "spline_fit" is contained

[brbr4]

when I use dwg_read_file() to get a POLYLINE_2D Entity which has flag "spline_fit", I will get all points contain points on cruve and points for control(Bezier), how to separate them?

[brbr4]

I have solved this problem.
when i got pts from POLYLINE_2D Entity::vertex , all points have the same flag;
but when got objects directly by VERTEX_2D , I can get curve points and control points with different flag(one is 8 and another is 16, when got from POLYLINE_2D Entity::vertex they are both 10)
this maybe a tiny bug?