@ ProgramNode (location: (0...37))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...37))
    └── body: (length: 2)
        ├── @ CallNode (location: (0...21))
        │   ├── receiver: ∅
        │   ├── call_operator_loc: ∅
        │   ├── message_loc: (0...2) = "td"
        │   ├── opening_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (3...21))
        │   │   └── arguments: (length: 1)
        │   │       └── @ CallNode (location: (3...21))
        │   │           ├── receiver:
        │   │           │   @ ParenthesesNode (location: (3...10))
        │   │           │   ├── body:
        │   │           │   │   @ StatementsNode (location: (4...9))
        │   │           │   │   └── body: (length: 1)
        │   │           │   │       └── @ IntegerNode (location: (4...9))
        │   │           │   │           └── flags: decimal
        │   │           │   ├── opening_loc: (3...4) = "("
        │   │           │   └── closing_loc: (9...10) = ")"
        │   │           ├── call_operator_loc: (10...11) = "."
        │   │           ├── message_loc: (11...19) = "toString"
        │   │           ├── opening_loc: (19...20) = "("
        │   │           ├── arguments: ∅
        │   │           ├── closing_loc: (20...21) = ")"
        │   │           ├── block: ∅
        │   │           ├── flags: ∅
        │   │           └── name: "toString"
        │   ├── closing_loc: ∅
        │   ├── block: ∅
        │   ├── flags: ∅
        │   └── name: "td"
        └── @ CallNode (location: (23...37))
            ├── receiver:
            │   @ CallNode (location: (23...25))
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── message_loc: (23...25) = "td"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: variable_call
            │   └── name: "td"
            ├── call_operator_loc: (25...26) = "."
            ├── message_loc: (26...29) = "num"
            ├── opening_loc: ∅
            ├── arguments: ∅
            ├── closing_loc: ∅
            ├── block:
            │   @ BlockNode (location: (30...37))
            │   ├── locals: []
            │   ├── parameters: ∅
            │   ├── body: ∅
            │   ├── opening_loc: (30...32) = "do"
            │   └── closing_loc: (34...37) = "end"
            ├── flags: ∅
            └── name: "num"
