0(1) element: null
1(2) element: PyMatchStatement
2(3,17) refutable pattern: [x] | (foo.bar as x)
3(4,6) refutable pattern: [x]
4(5) WRITE ACCESS: x
5(15) matched pattern: [x]
6(7,17) refutable pattern: (foo.bar as x)
7(8,17) refutable pattern: foo.bar as x
8(9,17) refutable pattern: foo.bar
9(10) READ ACCESS: foo
10(11) matched pattern: foo.bar
11(12) WRITE ACCESS: x
12(13) matched pattern: foo.bar as x
13(14) matched pattern: (foo.bar as x)
14(15) matched pattern: [x] | (foo.bar as x)
15(16) element: PyExpressionStatement
16(17) READ ACCESS: y
17(18) element: PyExpressionStatement
18(19) READ ACCESS: z
19() element: null