@ ProgramNode (location: (1,0)-(3,11))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(3,11))
    └── body: (length: 3)
        ├── @ YieldNode (location: (1,0)-(1,5))
        │   ├── keyword_loc: (1,0)-(1,5) = "yield"
        │   ├── lparen_loc: ∅
        │   ├── arguments: ∅
        │   └── rparen_loc: ∅
        ├── @ YieldNode (location: (2,0)-(2,8))
        │   ├── keyword_loc: (2,0)-(2,5) = "yield"
        │   ├── lparen_loc: (2,5)-(2,6) = "("
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (2,6)-(2,7))
        │   │   ├── flags: ∅
        │   │   └── arguments: (length: 1)
        │   │       └── @ CallNode (location: (2,6)-(2,7))
        │   │           ├── flags: variable_call, ignore_visibility
        │   │           ├── receiver: ∅
        │   │           ├── call_operator_loc: ∅
        │   │           ├── name: :a
        │   │           ├── message_loc: (2,6)-(2,7) = "a"
        │   │           ├── opening_loc: ∅
        │   │           ├── arguments: ∅
        │   │           ├── closing_loc: ∅
        │   │           └── block: ∅
        │   └── rparen_loc: (2,7)-(2,8) = ")"
        └── @ YieldNode (location: (3,0)-(3,11))
            ├── keyword_loc: (3,0)-(3,5) = "yield"
            ├── lparen_loc: (3,5)-(3,6) = "("
            ├── arguments:
            │   @ ArgumentsNode (location: (3,6)-(3,10))
            │   ├── flags: ∅
            │   └── arguments: (length: 2)
            │       ├── @ CallNode (location: (3,6)-(3,7))
            │       │   ├── flags: variable_call, ignore_visibility
            │       │   ├── receiver: ∅
            │       │   ├── call_operator_loc: ∅
            │       │   ├── name: :a
            │       │   ├── message_loc: (3,6)-(3,7) = "a"
            │       │   ├── opening_loc: ∅
            │       │   ├── arguments: ∅
            │       │   ├── closing_loc: ∅
            │       │   └── block: ∅
            │       └── @ CallNode (location: (3,9)-(3,10))
            │           ├── flags: variable_call, ignore_visibility
            │           ├── receiver: ∅
            │           ├── call_operator_loc: ∅
            │           ├── name: :b
            │           ├── message_loc: (3,9)-(3,10) = "b"
            │           ├── opening_loc: ∅
            │           ├── arguments: ∅
            │           ├── closing_loc: ∅
            │           └── block: ∅
            └── rparen_loc: (3,10)-(3,11) = ")"