0(1) element: null
1(2) element: PyWhileStatement
2(3,4) READ ACCESS: x
3(17) element: null. Condition: x:false
4(5) element: null. Condition: x:true
5(6) ASSERTTYPE ACCESS: x
6(7) element: PyStatementList
7(8) element: PyMatchStatement
8(9) READ ACCESS: x
9(10,14) refutable pattern: 42
10(11) matched pattern: 42
11(12) ASSERTTYPE ACCESS: x
12(13) element: PyStatementList
13(17) element: PyBreakStatement
14(15) ASSERTTYPE ACCESS: x
15(16) element: PyExpressionStatement
16(1) READ ACCESS: y
17(18) element: PyExpressionStatement
18(19) READ ACCESS: z
19() element: null