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