0(1) element: null
1(2) element: PyMatchStatement
2(3) refutable pattern: _ | 42
3(6) element: PyWildcardPattern
4(5,9) refutable pattern: 42
5(6) matched pattern: 42
6(7) matched pattern: _ | 42
7(8) element: PyExpressionStatement
8(9) READ ACCESS: y
9(10) element: PyExpressionStatement
10(11) READ ACCESS: z
11() element: null