@ ProgramNode (location: (1,0)-(1,24))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,24))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ IfNode (location: (1,0)-(1,24))
            ├── flags: newline
            ├── if_keyword_loc: (1,0)-(1,2) = "if"
            ├── predicate:
            │   @ CallNode (location: (1,3)-(1,15))
            │   ├── flags: ignore_visibility
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── name: :test
            │   ├── message_loc: (1,3)-(1,7) = "test"
            │   ├── opening_loc: ∅
            │   ├── arguments:
            │   │   @ ArgumentsNode (location: (1,8)-(1,15))
            │   │   ├── flags: ∅
            │   │   └── arguments: (length: 2)
            │   │       ├── @ StringNode (location: (1,8)-(1,10))
            │   │       │   ├── flags: ∅
            │   │       │   ├── opening_loc: (1,8)-(1,9) = "?"
            │   │       │   ├── content_loc: (1,9)-(1,10) = "d"
            │   │       │   ├── closing_loc: ∅
            │   │       │   └── unescaped: "d"
            │   │       └── @ CallNode (location: (1,12)-(1,15))
            │   │           ├── flags: variable_call, ignore_visibility
            │   │           ├── receiver: ∅
            │   │           ├── call_operator_loc: ∅
            │   │           ├── name: :dir
            │   │           ├── message_loc: (1,12)-(1,15) = "dir"
            │   │           ├── opening_loc: ∅
            │   │           ├── arguments: ∅
            │   │           ├── closing_loc: ∅
            │   │           └── block: ∅
            │   ├── closing_loc: ∅
            │   └── block: ∅
            ├── then_keyword_loc: (1,16)-(1,20) = "then"
            ├── statements: ∅
            ├── subsequent: ∅
            └── end_keyword_loc: (1,21)-(1,24) = "end"
