{"ast_node_type":"other","tokens":[{"end":14,"kind":"keyword","start":0,"text":"//"}]}
            //
            //   impl<T, U: Unsize<V>, V> CoerceUnsized<Foo<T, V>> for Foo<T, U> {}
            // Here `U = [i32; 3]` and `V = [i32]`. At runtime,