@ ProgramNode (location: (1,0)-(1,18))
├── locals: [:a, :b]
└── statements:
    @ StatementsNode (location: (1,0)-(1,18))
    └── body: (length: 1)
        └── @ MultiWriteNode (location: (1,0)-(1,18))
            ├── lefts: (length: 2)
            │   ├── @ LocalVariableTargetNode (location: (1,0)-(1,1))
            │   │   ├── name: :a
            │   │   └── depth: 0
            │   └── @ LocalVariableTargetNode (location: (1,3)-(1,4))
            │       ├── name: :b
            │       └── depth: 0
            ├── rest: ∅
            ├── rights: (length: 0)
            ├── lparen_loc: ∅
            ├── rparen_loc: ∅
            ├── operator_loc: (1,5)-(1,6) = "="
            └── value:
                @ RescueModifierNode (location: (1,7)-(1,18))
                ├── expression:
                │   @ CallNode (location: (1,7)-(1,8))
                │   ├── flags: variable_call
                │   ├── receiver: ∅
                │   ├── call_operator_loc: ∅
                │   ├── name: :f
                │   ├── message_loc: (1,7)-(1,8) = "f"
                │   ├── opening_loc: ∅
                │   ├── arguments: ∅
                │   ├── closing_loc: ∅
                │   └── block: ∅
                ├── keyword_loc: (1,9)-(1,15) = "rescue"
                └── rescue_expression:
                    @ IntegerNode (location: (1,16)-(1,18))
                    └── flags: decimal
