@ ProgramNode (location: (0...48))
├── locals: [:a]
└── statements:
    @ StatementsNode (location: (0...48))
    └── body: (length: 2)
        ├── @ ForNode (location: (0...24))
        │   ├── index:
        │   │   @ MultiTargetNode (location: (4...5))
        │   │   ├── targets: (length: 1)
        │   │   │   └── @ LocalVariableTargetNode (location: (4...5))
        │   │   │       ├── name: :a
        │   │   │       └── depth: 0
        │   │   ├── lparen_loc: ∅
        │   │   └── rparen_loc: ∅
        │   ├── collection:
        │   │   @ CallNode (location: (9...12))
        │   │   ├── receiver: ∅
        │   │   ├── call_operator_loc: ∅
        │   │   ├── message_loc: (9...12) = "foo"
        │   │   ├── opening_loc: ∅
        │   │   ├── arguments: ∅
        │   │   ├── closing_loc: ∅
        │   │   ├── block: ∅
        │   │   ├── flags: variable_call
        │   │   └── name: "foo"
        │   ├── statements:
        │   │   @ StatementsNode (location: (16...19))
        │   │   └── body: (length: 1)
        │   │       └── @ CallNode (location: (16...19))
        │   │           ├── receiver: ∅
        │   │           ├── call_operator_loc: ∅
        │   │           ├── message_loc: (16...17) = "p"
        │   │           ├── opening_loc: ∅
        │   │           ├── arguments:
        │   │           │   @ ArgumentsNode (location: (18...19))
        │   │           │   └── arguments: (length: 1)
        │   │           │       └── @ LocalVariableReadNode (location: (18...19))
        │   │           │           ├── name: :a
        │   │           │           └── depth: 0
        │   │           ├── closing_loc: ∅
        │   │           ├── block: ∅
        │   │           ├── flags: ∅
        │   │           └── name: "p"
        │   ├── for_keyword_loc: (0...3) = "for"
        │   ├── in_keyword_loc: (6...8) = "in"
        │   ├── do_keyword_loc: (13...15) = "do"
        │   └── end_keyword_loc: (21...24) = "end"
        └── @ ForNode (location: (26...48))
            ├── index:
            │   @ MultiTargetNode (location: (30...31))
            │   ├── targets: (length: 1)
            │   │   └── @ LocalVariableTargetNode (location: (30...31))
            │   │       ├── name: :a
            │   │       └── depth: 0
            │   ├── lparen_loc: ∅
            │   └── rparen_loc: ∅
            ├── collection:
            │   @ CallNode (location: (35...38))
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── message_loc: (35...38) = "foo"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: variable_call
            │   └── name: "foo"
            ├── statements:
            │   @ StatementsNode (location: (40...43))
            │   └── body: (length: 1)
            │       └── @ CallNode (location: (40...43))
            │           ├── receiver: ∅
            │           ├── call_operator_loc: ∅
            │           ├── message_loc: (40...41) = "p"
            │           ├── opening_loc: ∅
            │           ├── arguments:
            │           │   @ ArgumentsNode (location: (42...43))
            │           │   └── arguments: (length: 1)
            │           │       └── @ LocalVariableReadNode (location: (42...43))
            │           │           ├── name: :a
            │           │           └── depth: 0
            │           ├── closing_loc: ∅
            │           ├── block: ∅
            │           ├── flags: ∅
            │           └── name: "p"
            ├── for_keyword_loc: (26...29) = "for"
            ├── in_keyword_loc: (32...34) = "in"
            ├── do_keyword_loc: ∅
            └── end_keyword_loc: (45...48) = "end"
