Removing surface and point after creating Volume

[mohammad200h]

Hi, I am creating a volume using the following code

import pygmsh

with pygmsh.geo.Geometry() as geom:
    poly = geom.add_polygon(
        [
            [0.0, 0.0],
            [1.0, -0.2],
            [1.1, 1.2],
            [0.1, 0.7],
        ],
        mesh_size=0.1,
    )
    geom.extrude(poly, [0.0, 0.3, 1.0], num_layers=5,recombine=True)
    mesh = geom.generate_mesh()


    pygmsh.write("test.msh")

When I view test.msh in gmsh app I see that it has created 8 points, 12 curve,6 surface and 1 Volume.

How can i remove points, curves and surface and only keep the volume?

Thanks :)