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