@ ProgramNode (location: (0...15))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...15))
    └── body: (length: 2)
        ├── @ CallNode (location: (0...6))
        │   ├── receiver:
        │   │   @ CallNode (location: (0...1))
        │   │   ├── receiver: ∅
        │   │   ├── call_operator_loc: ∅
        │   │   ├── message_loc: (0...1) = "f"
        │   │   ├── opening_loc: ∅
        │   │   ├── arguments: ∅
        │   │   ├── closing_loc: ∅
        │   │   ├── block: ∅
        │   │   ├── flags: variable_call
        │   │   └── name: "f"
        │   ├── call_operator_loc: (1...2) = "."
        │   ├── message_loc: ∅
        │   ├── opening_loc: (2...3) = "("
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (3...5))
        │   │   └── arguments: (length: 1)
        │   │       └── @ IntegerNode (location: (3...5))
        │   │           └── flags: decimal
        │   ├── closing_loc: (5...6) = ")"
        │   ├── block: ∅
        │   ├── flags: ∅
        │   └── name: "call"
        └── @ CallNode (location: (8...15))
            ├── receiver:
            │   @ CallNode (location: (8...9))
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── message_loc: (8...9) = "f"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: variable_call
            │   └── name: "f"
            ├── call_operator_loc: (9...11) = "::"
            ├── message_loc: ∅
            ├── opening_loc: (11...12) = "("
            ├── arguments:
            │   @ ArgumentsNode (location: (12...14))
            │   └── arguments: (length: 1)
            │       └── @ IntegerNode (location: (12...14))
            │           └── flags: decimal
            ├── closing_loc: (14...15) = ")"
            ├── block: ∅
            ├── flags: ∅
            └── name: "call"
