@ ProgramNode (location: (1,0)-(12,11))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(12,11))
    └── body: (length: 5)
        ├── @ NilNode (location: (1,0)-(1,3))
        ├── @ ParenthesesNode (location: (3,0)-(3,2))
        │   ├── body: ∅
        │   ├── opening_loc: (3,0)-(3,1) = "("
        │   └── closing_loc: (3,1)-(3,2) = ")"
        ├── @ ParenthesesNode (location: (5,0)-(8,1))
        │   ├── body: ∅
        │   ├── opening_loc: (5,0)-(5,1) = "("
        │   └── closing_loc: (8,0)-(8,1) = ")"
        ├── @ PostExecutionNode (location: (10,0)-(10,9))
        │   ├── statements:
        │   │   @ StatementsNode (location: (10,6)-(10,7))
        │   │   └── body: (length: 1)
        │   │       └── @ IntegerNode (location: (10,6)-(10,7))
        │   │           ├── flags: decimal
        │   │           └── value: 1
        │   ├── keyword_loc: (10,0)-(10,3) = "END"
        │   ├── opening_loc: (10,4)-(10,5) = "{"
        │   └── closing_loc: (10,8)-(10,9) = "}"
        └── @ PreExecutionNode (location: (12,0)-(12,11))
            ├── statements:
            │   @ StatementsNode (location: (12,8)-(12,9))
            │   └── body: (length: 1)
            │       └── @ IntegerNode (location: (12,8)-(12,9))
            │           ├── flags: decimal
            │           └── value: 1
            ├── keyword_loc: (12,0)-(12,5) = "BEGIN"
            ├── opening_loc: (12,6)-(12,7) = "{"
            └── closing_loc: (12,10)-(12,11) = "}"