@ ProgramNode (location: (1,0)-(1,16))
├── flags: ∅
├── locals: [:foo, :bar]
└── statements:
    @ StatementsNode (location: (1,0)-(1,16))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ MultiWriteNode (location: (1,0)-(1,16))
            ├── flags: newline
            ├── lefts: (length: 2)
            │   ├── @ LocalVariableTargetNode (location: (1,0)-(1,3))
            │   │   ├── flags: ∅
            │   │   ├── name: :foo
            │   │   └── depth: 0
            │   └── @ LocalVariableTargetNode (location: (1,5)-(1,8))
            │       ├── flags: ∅
            │       ├── name: :bar
            │       └── depth: 0
            ├── rest: ∅
            ├── rights: (length: 0)
            ├── lparen_loc: ∅
            ├── rparen_loc: ∅
            ├── operator_loc: (1,9)-(1,10) = "="
            └── value:
                @ CallNode (location: (1,11)-(1,16))
                ├── flags: ignore_visibility
                ├── receiver: ∅
                ├── call_operator_loc: ∅
                ├── name: :m
                ├── message_loc: (1,11)-(1,12) = "m"
                ├── opening_loc: ∅
                ├── arguments:
                │   @ ArgumentsNode (location: (1,13)-(1,16))
                │   ├── flags: ∅
                │   └── arguments: (length: 1)
                │       └── @ LocalVariableReadNode (location: (1,13)-(1,16))
                │           ├── flags: ∅
                │           ├── name: :foo
                │           └── depth: 0
                ├── closing_loc: ∅
                └── block: ∅
