@ ProgramNode (location: (0...100))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...100))
    └── body: (length: 6)
        ├── @ YieldNode (location: (0...16))
        │   ├── keyword_loc: (0...5) = "yield"
        │   ├── lparen_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (6...16))
        │   │   └── arguments: (length: 2)
        │   │       ├── @ IntegerNode (location: (6...7))
        │   │       │   └── flags: decimal
        │   │       └── @ KeywordHashNode (location: (9...16))
        │   │           └── elements: (length: 1)
        │   │               └── @ AssocNode (location: (9...16))
        │   │                   ├── key:
        │   │                   │   @ SymbolNode (location: (9...11))
        │   │                   │   ├── opening_loc: (9...10) = ":"
        │   │                   │   ├── value_loc: (10...11) = "z"
        │   │                   │   ├── closing_loc: ∅
        │   │                   │   └── unescaped: "z"
        │   │                   ├── value:
        │   │                   │   @ IntegerNode (location: (15...16))
        │   │                   │   └── flags: decimal
        │   │                   └── operator_loc: (12...14) = "=>"
        │   └── rparen_loc: ∅
        ├── @ YieldNode (location: (18...43))
        │   ├── keyword_loc: (18...23) = "yield"
        │   ├── lparen_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (24...43))
        │   │   └── arguments: (length: 2)
        │   │       ├── @ IntegerNode (location: (24...25))
        │   │       │   └── flags: decimal
        │   │       └── @ KeywordHashNode (location: (27...43))
        │   │           └── elements: (length: 2)
        │   │               ├── @ AssocNode (location: (27...34))
        │   │               │   ├── key:
        │   │               │   │   @ SymbolNode (location: (27...29))
        │   │               │   │   ├── opening_loc: (27...28) = ":"
        │   │               │   │   ├── value_loc: (28...29) = "z"
        │   │               │   │   ├── closing_loc: ∅
        │   │               │   │   └── unescaped: "z"
        │   │               │   ├── value:
        │   │               │   │   @ IntegerNode (location: (33...34))
        │   │               │   │   └── flags: decimal
        │   │               │   └── operator_loc: (30...32) = "=>"
        │   │               └── @ AssocNode (location: (36...43))
        │   │                   ├── key:
        │   │                   │   @ SymbolNode (location: (36...38))
        │   │                   │   ├── opening_loc: (36...37) = ":"
        │   │                   │   ├── value_loc: (37...38) = "w"
        │   │                   │   ├── closing_loc: ∅
        │   │                   │   └── unescaped: "w"
        │   │                   ├── value:
        │   │                   │   @ IntegerNode (location: (42...43))
        │   │                   │   └── flags: decimal
        │   │                   └── operator_loc: (39...41) = "=>"
        │   └── rparen_loc: ∅
        ├── @ YieldNode (location: (45...58))
        │   ├── keyword_loc: (45...50) = "yield"
        │   ├── lparen_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (51...58))
        │   │   └── arguments: (length: 1)
        │   │       └── @ CallNode (location: (51...58))
        │   │           ├── receiver: ∅
        │   │           ├── call_operator_loc: ∅
        │   │           ├── message_loc: (51...52) = "y"
        │   │           ├── opening_loc: ∅
        │   │           ├── arguments:
        │   │           │   @ ArgumentsNode (location: (53...58))
        │   │           │   └── arguments: (length: 1)
        │   │           │       └── @ KeywordHashNode (location: (53...58))
        │   │           │           └── elements: (length: 1)
        │   │           │               └── @ AssocNode (location: (53...58))
        │   │           │                   ├── key:
        │   │           │                   │   @ SymbolNode (location: (53...55))
        │   │           │                   │   ├── opening_loc: (53...54) = ":"
        │   │           │                   │   ├── value_loc: (54...55) = "z"
        │   │           │                   │   ├── closing_loc: ∅
        │   │           │                   │   └── unescaped: "z"
        │   │           │                   ├── value:
        │   │           │                   │   @ IntegerNode (location: (57...58))
        │   │           │                   │   └── flags: decimal
        │   │           │                   └── operator_loc: (55...57) = "=>"
        │   │           ├── closing_loc: ∅
        │   │           ├── block: ∅
        │   │           ├── flags: ∅
        │   │           └── name: "y"
        │   └── rparen_loc: ∅
        ├── @ YieldNode (location: (60...71))
        │   ├── keyword_loc: (60...65) = "yield"
        │   ├── lparen_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (66...71))
        │   │   └── arguments: (length: 1)
        │   │       └── @ CallNode (location: (66...71))
        │   │           ├── receiver: ∅
        │   │           ├── call_operator_loc: ∅
        │   │           ├── message_loc: (66...67) = "y"
        │   │           ├── opening_loc: ∅
        │   │           ├── arguments:
        │   │           │   @ ArgumentsNode (location: (68...71))
        │   │           │   └── arguments: (length: 1)
        │   │           │       └── @ KeywordHashNode (location: (68...71))
        │   │           │           └── elements: (length: 1)
        │   │           │               └── @ AssocNode (location: (68...71))
        │   │           │                   ├── key:
        │   │           │                   │   @ SymbolNode (location: (68...70))
        │   │           │                   │   ├── opening_loc: ∅
        │   │           │                   │   ├── value_loc: (68...69) = "z"
        │   │           │                   │   ├── closing_loc: (69...70) = ":"
        │   │           │                   │   └── unescaped: "z"
        │   │           │                   ├── value:
        │   │           │                   │   @ IntegerNode (location: (70...71))
        │   │           │                   │   └── flags: decimal
        │   │           │                   └── operator_loc: ∅
        │   │           ├── closing_loc: ∅
        │   │           ├── block: ∅
        │   │           ├── flags: ∅
        │   │           └── name: "y"
        │   └── rparen_loc: ∅
        ├── @ YieldNode (location: (73...85))
        │   ├── keyword_loc: (73...78) = "yield"
        │   ├── lparen_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (79...85))
        │   │   └── arguments: (length: 1)
        │   │       └── @ CallNode (location: (79...85))
        │   │           ├── receiver: ∅
        │   │           ├── call_operator_loc: ∅
        │   │           ├── message_loc: (79...80) = "y"
        │   │           ├── opening_loc: (80...81) = "("
        │   │           ├── arguments:
        │   │           │   @ ArgumentsNode (location: (81...84))
        │   │           │   └── arguments: (length: 1)
        │   │           │       └── @ KeywordHashNode (location: (81...84))
        │   │           │           └── elements: (length: 1)
        │   │           │               └── @ AssocNode (location: (81...84))
        │   │           │                   ├── key:
        │   │           │                   │   @ SymbolNode (location: (81...83))
        │   │           │                   │   ├── opening_loc: ∅
        │   │           │                   │   ├── value_loc: (81...82) = "z"
        │   │           │                   │   ├── closing_loc: (82...83) = ":"
        │   │           │                   │   └── unescaped: "z"
        │   │           │                   ├── value:
        │   │           │                   │   @ IntegerNode (location: (83...84))
        │   │           │                   │   └── flags: decimal
        │   │           │                   └── operator_loc: ∅
        │   │           ├── closing_loc: (84...85) = ")"
        │   │           ├── block: ∅
        │   │           ├── flags: ∅
        │   │           └── name: "y"
        │   └── rparen_loc: ∅
        └── @ YieldNode (location: (87...100))
            ├── keyword_loc: (87...92) = "yield"
            ├── lparen_loc: ∅
            ├── arguments:
            │   @ ArgumentsNode (location: (93...100))
            │   └── arguments: (length: 1)
            │       └── @ CallNode (location: (93...100))
            │           ├── receiver: ∅
            │           ├── call_operator_loc: ∅
            │           ├── message_loc: (93...94) = "y"
            │           ├── opening_loc: (94...95) = "("
            │           ├── arguments:
            │           │   @ ArgumentsNode (location: (95...99))
            │           │   └── arguments: (length: 1)
            │           │       └── @ KeywordHashNode (location: (95...99))
            │           │           └── elements: (length: 1)
            │           │               └── @ AssocNode (location: (95...99))
            │           │                   ├── key:
            │           │                   │   @ CallNode (location: (95...96))
            │           │                   │   ├── receiver: ∅
            │           │                   │   ├── call_operator_loc: ∅
            │           │                   │   ├── message_loc: (95...96) = "z"
            │           │                   │   ├── opening_loc: ∅
            │           │                   │   ├── arguments: ∅
            │           │                   │   ├── closing_loc: ∅
            │           │                   │   ├── block: ∅
            │           │                   │   ├── flags: variable_call
            │           │                   │   └── name: "z"
            │           │                   ├── value:
            │           │                   │   @ IntegerNode (location: (98...99))
            │           │                   │   └── flags: decimal
            │           │                   └── operator_loc: (96...98) = "=>"
            │           ├── closing_loc: (99...100) = ")"
            │           ├── block: ∅
            │           ├── flags: ∅
            │           └── name: "y"
            └── rparen_loc: ∅
