@ ProgramNode (location: (0...39))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...39))
    └── body: (length: 1)
        └── @ CaseNode (location: (0...39))
            ├── predicate:
            │   @ HashNode (location: (5...11))
            │   ├── opening_loc: (5...6) = "{"
            │   ├── elements: (length: 1)
            │   │   └── @ AssocNode (location: (6...10))
            │   │       ├── key:
            │   │       │   @ SymbolNode (location: (6...8))
            │   │       │   ├── opening_loc: ∅
            │   │       │   ├── value_loc: (6...7) = "a"
            │   │       │   ├── closing_loc: (7...8) = ":"
            │   │       │   └── unescaped: "a"
            │   │       ├── value:
            │   │       │   @ IntegerNode (location: (9...10))
            │   │       │   └── flags: decimal
            │   │       └── operator_loc: ∅
            │   └── closing_loc: (10...11) = "}"
            ├── conditions: (length: 1)
            │   └── @ InNode (location: (12...35))
            │       ├── pattern:
            │       │   @ HashPatternNode (location: (15...28))
            │       │   ├── constant: ∅
            │       │   ├── assocs: (length: 2)
            │       │   │   ├── @ AssocNode (location: (16...20))
            │       │   │   │   ├── key:
            │       │   │   │   │   @ SymbolNode (location: (16...18))
            │       │   │   │   │   ├── opening_loc: ∅
            │       │   │   │   │   ├── value_loc: (16...17) = "a"
            │       │   │   │   │   ├── closing_loc: (17...18) = ":"
            │       │   │   │   │   └── unescaped: "a"
            │       │   │   │   ├── value:
            │       │   │   │   │   @ IntegerNode (location: (19...20))
            │       │   │   │   │   └── flags: decimal
            │       │   │   │   └── operator_loc: ∅
            │       │   │   └── @ NoKeywordsParameterNode (location: (22...27))
            │       │   │       ├── operator_loc: (22...24) = "**"
            │       │   │       └── keyword_loc: (24...27) = "nil"
            │       │   ├── kwrest: ∅
            │       │   ├── opening_loc: (15...16) = "{"
            │       │   └── closing_loc: (27...28) = "}"
            │       ├── statements:
            │       │   @ StatementsNode (location: (31...35))
            │       │   └── body: (length: 1)
            │       │       └── @ TrueNode (location: (31...35))
            │       ├── in_loc: (12...14) = "in"
            │       └── then_loc: ∅
            ├── consequent: ∅
            ├── case_keyword_loc: (0...4) = "case"
            └── end_keyword_loc: (36...39) = "end"
