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