Tutorial 4.8 call by value vs reference is confusing
Documentation
The part about how arguments are passed in Section 4.8 (by value vs by reference) is written in a confusing way and there is even a footnote admitting to it
IMO an improvement would be along the lines:
Arguments are always passed using call by value. For objects that are passed this value consists of a reference to that object. Which means that mutations to the object are visible outside, reassignments of another reference to the variable inside the function are not. insert example