@ ProgramNode (location: (1,0)-(1,11))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,11))
    └── body: (length: 1)
        └── @ ArrayNode (location: (1,0)-(1,11))
            ├── flags: ∅
            ├── elements: (length: 2)
            │   ├── @ IntegerNode (location: (1,1)-(1,2))
            │   │   ├── flags: decimal
            │   │   └── value: 1
            │   └── @ KeywordHashNode (location: (1,4)-(1,10))
            │       ├── flags: ∅
            │       └── elements: (length: 1)
            │           └── @ AssocNode (location: (1,4)-(1,10))
            │               ├── key:
            │               │   @ IntegerNode (location: (1,4)-(1,5))
            │               │   ├── flags: decimal
            │               │   └── value: 2
            │               ├── value:
            │               │   @ IntegerNode (location: (1,9)-(1,10))
            │               │   ├── flags: decimal
            │               │   └── value: 3
            │               └── operator_loc: (1,6)-(1,8) = "=>"
            ├── opening_loc: (1,0)-(1,1) = "["
            └── closing_loc: (1,10)-(1,11) = "]"