@ ProgramNode (location: (0...2))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...2))
    └── body: (length: 1)
        └── @ ParenthesesNode (location: (0...2))
            ├── body: ∅
            ├── opening_loc: (0...1) = "("
            └── closing_loc: (1...2) = ")"
