original.name="Reference_Valid_34"
======
>>> main.whiley
type Node is &{ List next, int data }
type List is null | Node
method next(List n):
skip
method visit(List s):
//
next(s)
next(s)
public export method test():
List l1 = new Node{ next: null, data: 0}
List l2 = new Node{ next: null, data: 1}
//
visit(l1)
// Don't know much about l1 here
assert l1->next != l2
// Should know l2 is unchanged
assert l2->data == 1
---