@ ProgramNode (location: (1,0)-(4,7))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(4,7))
    └── body: (length: 4)
        ├── @ SourceEncodingNode (location: (1,0)-(1,12))
        ├── @ SourceFileNode (location: (2,0)-(2,8))
        │   └── filepath: "unparser/corpus/literal/pragma.txt"
        ├── @ SourceLineNode (location: (3,0)-(3,8))
        └── @ CallNode (location: (4,0)-(4,7))
            ├── flags: variable_call
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── name: :__dir__
            ├── message_loc: (4,0)-(4,7) = "__dir__"
            ├── opening_loc: ∅
            ├── arguments: ∅
            ├── closing_loc: ∅
            └── block: ∅
