@ ProgramNode (location: (0...6))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...6))
    └── body: (length: 1)
        └── @ ArrayNode (location: (0...6))
            ├── elements: (length: 2)
            │   ├── @ IntegerNode (location: (1...2))
            │   │   └── flags: decimal
            │   └── @ IntegerNode (location: (4...5))
            │       └── flags: decimal
            ├── opening_loc: (0...1) = "["
            └── closing_loc: (5...6) = "]"
