@ ProgramNode (location: (0...24))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...24))
    └── body: (length: 1)
        └── @ IfNode (location: (0...24))
            ├── if_keyword_loc: (0...2) = "if"
            ├── predicate:
            │   @ CallNode (location: (3...15))
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── message_loc: (3...7) = "test"
            │   ├── opening_loc: ∅
            │   ├── arguments:
            │   │   @ ArgumentsNode (location: (8...15))
            │   │   └── arguments: (length: 2)
            │   │       ├── @ StringNode (location: (8...10))
            │   │       │   ├── opening_loc: (8...9) = "?"
            │   │       │   ├── content_loc: (9...10) = "d"
            │   │       │   ├── closing_loc: ∅
            │   │       │   └── unescaped: "d"
            │   │       └── @ CallNode (location: (12...15))
            │   │           ├── receiver: ∅
            │   │           ├── call_operator_loc: ∅
            │   │           ├── message_loc: (12...15) = "dir"
            │   │           ├── opening_loc: ∅
            │   │           ├── arguments: ∅
            │   │           ├── closing_loc: ∅
            │   │           ├── block: ∅
            │   │           ├── flags: variable_call
            │   │           └── name: "dir"
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: ∅
            │   └── name: "test"
            ├── statements: ∅
            ├── consequent: ∅
            └── end_keyword_loc: (21...24) = "end"
