0(1) element: null
1(2) element: PyForStatement
2(3,14) READ ACCESS: lines
3(4) element: PyTargetExpression: line
4(5) WRITE ACCESS: line
5(6) element: PyIfStatement
6(7,9) READ ACCESS: line
7(8) element: null. Condition: line == '@':false
8(3,14) ASSERTTYPE ACCESS: line
9(10) element: null. Condition: line == '@':true
10(11) ASSERTTYPE ACCESS: line
11(12) element: PyStatementList
12(13) element: PyAssignmentStatement
13(3,14) WRITE ACCESS: head
14() element: null