@ ProgramNode (location: (0...12))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...12))
    └── body: (length: 1)
        └── @ PreExecutionNode (location: (0...12))
            ├── statements:
            │   @ StatementsNode (location: (8...10))
            │   └── body: (length: 1)
            │       └── @ IntegerNode (location: (8...10))
            │           └── flags: decimal
            ├── keyword_loc: (0...5) = "BEGIN"
            ├── opening_loc: (6...7) = "{"
            └── closing_loc: (11...12) = "}"