@ ProgramNode (location: (1,0)-(5,18))
├── flags: ∅
├── locals: [:foo]
└── statements:
    @ StatementsNode (location: (1,0)-(5,18))
    ├── flags: ∅
    └── body: (length: 3)
        ├── @ MultiWriteNode (location: (1,0)-(1,17))
        │   ├── flags: newline
        │   ├── lefts: (length: 2)
        │   │   ├── @ CallTargetNode (location: (1,0)-(1,6))
        │   │   │   ├── flags: ignore_visibility
        │   │   │   ├── receiver:
        │   │   │   │   @ SelfNode (location: (1,0)-(1,4))
        │   │   │   │   └── flags: ∅
        │   │   │   ├── call_operator_loc: (1,4)-(1,5) = "."
        │   │   │   ├── name: :A=
        │   │   │   └── message_loc: (1,5)-(1,6) = "A"
        │   │   └── @ LocalVariableTargetNode (location: (1,8)-(1,11))
        │   │       ├── flags: ∅
        │   │       ├── name: :foo
        │   │       └── depth: 0
        │   ├── rest: ∅
        │   ├── rights: (length: 0)
        │   ├── lparen_loc: ∅
        │   ├── rparen_loc: ∅
        │   ├── operator_loc: (1,12)-(1,13) = "="
        │   └── value:
        │       @ LocalVariableReadNode (location: (1,14)-(1,17))
        │       ├── flags: ∅
        │       ├── name: :foo
        │       └── depth: 0
        ├── @ MultiWriteNode (location: (3,0)-(3,24))
        │   ├── flags: newline
        │   ├── lefts: (length: 2)
        │   │   ├── @ CallTargetNode (location: (3,0)-(3,6))
        │   │   │   ├── flags: ignore_visibility
        │   │   │   ├── receiver:
        │   │   │   │   @ SelfNode (location: (3,0)-(3,4))
        │   │   │   │   └── flags: ∅
        │   │   │   ├── call_operator_loc: (3,4)-(3,5) = "."
        │   │   │   ├── name: :a=
        │   │   │   └── message_loc: (3,5)-(3,6) = "a"
        │   │   └── @ IndexTargetNode (location: (3,8)-(3,18))
        │   │       ├── flags: attribute_write, ignore_visibility
        │   │       ├── receiver:
        │   │       │   @ SelfNode (location: (3,8)-(3,12))
        │   │       │   └── flags: ∅
        │   │       ├── opening_loc: (3,12)-(3,13) = "["
        │   │       ├── arguments:
        │   │       │   @ ArgumentsNode (location: (3,13)-(3,17))
        │   │       │   ├── flags: ∅
        │   │       │   └── arguments: (length: 2)
        │   │       │       ├── @ IntegerNode (location: (3,13)-(3,14))
        │   │       │       │   ├── flags: static_literal, decimal
        │   │       │       │   └── value: 1
        │   │       │       └── @ IntegerNode (location: (3,16)-(3,17))
        │   │       │           ├── flags: static_literal, decimal
        │   │       │           └── value: 2
        │   │       ├── closing_loc: (3,17)-(3,18) = "]"
        │   │       └── block: ∅
        │   ├── rest: ∅
        │   ├── rights: (length: 0)
        │   ├── lparen_loc: ∅
        │   ├── rparen_loc: ∅
        │   ├── operator_loc: (3,19)-(3,20) = "="
        │   └── value:
        │       @ LocalVariableReadNode (location: (3,21)-(3,24))
        │       ├── flags: ∅
        │       ├── name: :foo
        │       └── depth: 0
        └── @ MultiWriteNode (location: (5,0)-(5,18))
            ├── flags: newline
            ├── lefts: (length: 2)
            │   ├── @ CallTargetNode (location: (5,0)-(5,7))
            │   │   ├── flags: ignore_visibility
            │   │   ├── receiver:
            │   │   │   @ SelfNode (location: (5,0)-(5,4))
            │   │   │   └── flags: ∅
            │   │   ├── call_operator_loc: (5,4)-(5,6) = "::"
            │   │   ├── name: :a=
            │   │   └── message_loc: (5,6)-(5,7) = "a"
            │   └── @ LocalVariableTargetNode (location: (5,9)-(5,12))
            │       ├── flags: ∅
            │       ├── name: :foo
            │       └── depth: 0
            ├── rest: ∅
            ├── rights: (length: 0)
            ├── lparen_loc: ∅
            ├── rparen_loc: ∅
            ├── operator_loc: (5,13)-(5,14) = "="
            └── value:
                @ LocalVariableReadNode (location: (5,15)-(5,18))
                ├── flags: ∅
                ├── name: :foo
                └── depth: 0
