[Gmsh] Line In BoundingBox

[Ugis Lacis]

Dear Gmsh users and developers,

I am now trying to use the Gmsh OpenCascade factory and after some 
operations assign the needed physical tags to lines (I am working with a 
2D set-up). I have gone through tutorials and found the commands "Point 
In BoundingBox{}", and "Surface In BoundingBox{}" and "Volume In 
BoundingBox{}". However, I do not see anything similar to "Line In 
BoundingBox{}".

I have tried to use the following in my geo script:
ts() = Line In BoundingBox{xmin-eps, ymax-eps, 0.0,
                                           xmax+eps, ymax+eps, 0.0};
Physical Line(3) = {ts()};

No error is given, but the line within the box are not tagged with 
physical tag "3". Am I missing something about how "Line in 
BoundingBox{}" works, or is there some other function useful for this task?

I am using Gmsh 4.3.0.

Best wishes,
Ugis Lacis