@ ProgramNode (location: (0...43))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...43))
    └── body: (length: 3)
        ├── @ CallNode (location: (0...14))
        │   ├── receiver: ∅
        │   ├── call_operator_loc: ∅
        │   ├── message_loc: (0...1) = "f"
        │   ├── opening_loc: (1...2) = "("
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (2...13))
        │   │   └── arguments: (length: 1)
        │   │       └── @ KeywordHashNode (location: (2...13))
        │   │           └── elements: (length: 1)
        │   │               └── @ AssocNode (location: (2...13))
        │   │                   ├── key:
        │   │                   │   @ SymbolNode (location: (2...8))
        │   │                   │   ├── opening_loc: ∅
        │   │                   │   ├── value_loc: (2...7) = "state"
        │   │                   │   ├── closing_loc: (7...8) = ":"
        │   │                   │   └── unescaped: "state"
        │   │                   ├── value:
        │   │                   │   @ HashNode (location: (10...13))
        │   │                   │   ├── opening_loc: (10...11) = "{"
        │   │                   │   ├── elements: (length: 0)
        │   │                   │   └── closing_loc: (12...13) = "}"
        │   │                   └── operator_loc: ∅
        │   ├── closing_loc: (13...14) = ")"
        │   ├── block: ∅
        │   ├── flags: ∅
        │   └── name: "f"
        ├── @ CallNode (location: (16...29))
        │   ├── receiver: ∅
        │   ├── call_operator_loc: ∅
        │   ├── message_loc: (16...17) = "f"
        │   ├── opening_loc: (17...18) = "("
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (18...28))
        │   │   └── arguments: (length: 1)
        │   │       └── @ KeywordHashNode (location: (18...28))
        │   │           └── elements: (length: 1)
        │   │               └── @ AssocNode (location: (18...28))
        │   │                   ├── key:
        │   │                   │   @ SymbolNode (location: (18...24))
        │   │                   │   ├── opening_loc: ∅
        │   │                   │   ├── value_loc: (18...23) = "state"
        │   │                   │   ├── closing_loc: (23...24) = ":"
        │   │                   │   └── unescaped: "state"
        │   │                   ├── value:
        │   │                   │   @ HashNode (location: (25...28))
        │   │                   │   ├── opening_loc: (25...26) = "{"
        │   │                   │   ├── elements: (length: 0)
        │   │                   │   └── closing_loc: (27...28) = "}"
        │   │                   └── operator_loc: ∅
        │   ├── closing_loc: (28...29) = ")"
        │   ├── block: ∅
        │   ├── flags: ∅
        │   └── name: "f"
        └── @ CallNode (location: (31...43))
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── message_loc: (31...32) = "f"
            ├── opening_loc: (32...33) = "("
            ├── arguments:
            │   @ ArgumentsNode (location: (33...42))
            │   └── arguments: (length: 1)
            │       └── @ KeywordHashNode (location: (33...42))
            │           └── elements: (length: 1)
            │               └── @ AssocNode (location: (33...42))
            │                   ├── key:
            │                   │   @ SymbolNode (location: (33...39))
            │                   │   ├── opening_loc: ∅
            │                   │   ├── value_loc: (33...38) = "state"
            │                   │   ├── closing_loc: (38...39) = ":"
            │                   │   └── unescaped: "state"
            │                   ├── value:
            │                   │   @ HashNode (location: (40...42))
            │                   │   ├── opening_loc: (40...41) = "{"
            │                   │   ├── elements: (length: 0)
            │                   │   └── closing_loc: (41...42) = "}"
            │                   └── operator_loc: ∅
            ├── closing_loc: (42...43) = ")"
            ├── block: ∅
            ├── flags: ∅
            └── name: "f"
