BRepPrimAPI_MakePrism return Compound Shape

Hello.
I want to get the shape as one solid of the shell stretched.
When I tried following code, the result shape was compound shape.
How to get shape as one solid?

[shell]

[shape]

[code]

shape = BRepPrimAPI_MakePrism( shell, gp_Vec( srX, 0.0, 0.0 ) ).Shape();

Best regards.