0(1) element: null
1(2) element: PyWithStatement
2(4) READ ACCESS: cm1
3(14) exit context manager: cm1
4(3,6) READ ACCESS: cm2
5(14) exit context manager: cm2
6(3,5,8) READ ACCESS: cm3
7(14) exit context manager: cm3
8(9,3,5,7) element: PyAssertStatement
9(10,3,5,7) READ ACCESS: False
10(11,3,5,7) READ ACCESS: f
11(12,3,5,7) element: PyCallExpression: f
12(15,3,5,7) raise: PyAssertStatement
13(14,3,5,7) element: PyPrintStatement
14(15) element: PyPrintStatement
15() element: null