Test babylon transform node

[Dok11]

Hi!
The url https://doc.babylonjs.com/how_to/parenting currently is 404, so I updated it.

And one strange momemnt to me. I tried to write test case like this:

const scene = new Scene(subject);
const child = new AbstractMesh("Child", scene);
const parent = new AbstractMesh("Parent", scene);

child.rotationQuaternion = new Quaternion(0.1, 0.2, 0.3, 1);
child.setParent(parent);

After setParent the child.rotationQuaternion equals to {"_isDirty": true, "_w": 0.9193215324678584, "_x": 0.10613875217731637, "_y": 0.21264414489225805, "_z": 0.31622577190124856}
It happens after call composedMatrix.decompose() in the setParent() method.
I don't know, is this behaviour correct?

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