@ ProgramNode (location: (1,0)-(3,4))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(3,4))
    └── body: (length: 2)
        ├── @ CallNode (location: (1,0)-(1,6))
        │   ├── flags: ∅
        │   ├── receiver:
        │   │   @ ArrayNode (location: (1,0)-(1,4))
        │   │   ├── flags: ∅
        │   │   ├── elements: (length: 0)
        │   │   ├── opening_loc: (1,0)-(1,3) = "%w["
        │   │   └── closing_loc: (1,3)-(1,4) = "]"
        │   ├── call_operator_loc: (1,4)-(1,5) = "."
        │   ├── name: :b
        │   ├── message_loc: (1,5)-(1,6) = "b"
        │   ├── opening_loc: ∅
        │   ├── arguments: ∅
        │   ├── closing_loc: ∅
        │   └── block: ∅
        └── @ CallNode (location: (3,0)-(3,4))
            ├── flags: ∅
            ├── receiver:
            │   @ ArrayNode (location: (3,0)-(3,2))
            │   ├── flags: ∅
            │   ├── elements: (length: 0)
            │   ├── opening_loc: (3,0)-(3,1) = "["
            │   └── closing_loc: (3,1)-(3,2) = "]"
            ├── call_operator_loc: (3,2)-(3,3) = "."
            ├── name: :b
            ├── message_loc: (3,3)-(3,4) = "b"
            ├── opening_loc: ∅
            ├── arguments: ∅
            ├── closing_loc: ∅
            └── block: ∅