@ ProgramNode (location: (1,0)-(1,5))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,5))
    └── body: (length: 1)
        └── @ CallNode (location: (1,0)-(1,5))
            ├── flags: ∅
            ├── receiver:
            │   @ IntegerNode (location: (1,0)-(1,1))
            │   └── flags: decimal
            ├── call_operator_loc: (1,1)-(1,3) = "::"
            ├── name: :call
            ├── message_loc: ∅
            ├── opening_loc: (1,3)-(1,4) = "("
            ├── arguments: ∅
            ├── closing_loc: (1,4)-(1,5) = ")"
            └── block: ∅
