Compound.do_children_intersect has side effects

[bernhard-42]

Compound.do_children_intersect seems to have a side effect.

I use build123d/docs/tutorial_joints.py and add two debug statements:

diff --git a/docs/tutorial_joints.py b/docs/tutorial_joints.py
index e6d2fd3..b45e0f0 100644
--- a/docs/tutorial_joints.py
+++ b/docs/tutorial_joints.py
@@ -331,9 +331,11 @@ m6_screw.parent = box_assembly
 print(box_assembly.show_topology())

 # [Check that the components in the assembly don't intersect]
+print("DEBUG(1)", box.joints["hinge_attachment"].parent.volume)
 child_intersect, children, volume = box_assembly.do_children_intersect(
     include_parent=False
 )
+print("DEBUG(2)", box.joints["hinge_attachment"].parent.volume)
 print(f"do children intersect: {child_intersect}")
 if child_intersect:
     print(f"{children} by {volume:0.3f} mm^3")

It leads to the output

DEBUG(1) 1940751.7699835314
DEBUG(2) 0
do children intersect: False
``´