0(1) element: null
1(2) element: PyMatchStatement
2(3,19) refutable pattern: {'foo': 1, 'bar': foo.bar}
3(4,19) refutable pattern: 'foo': 1
4(5,19) refutable pattern: 'foo'
5(6) matched pattern: 'foo'
6(7,19) refutable pattern: 1
7(8) matched pattern: 1
8(9) matched pattern: 'foo': 1
9(10,19) refutable pattern: 'bar': foo.bar
10(11,19) refutable pattern: 'bar'
11(12) matched pattern: 'bar'
12(13,19) refutable pattern: foo.bar
13(14) READ ACCESS: foo
14(15) matched pattern: foo.bar
15(16) matched pattern: 'bar': foo.bar
16(17) matched pattern: {'foo': 1, 'bar': foo.bar}
17(18) element: PyExpressionStatement
18(19) READ ACCESS: x
19(20) element: PyExpressionStatement
20(21) READ ACCESS: y
21() element: null