@ ProgramNode (location: (0...3))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...3))
    └── body: (length: 1)
        └── @ SymbolNode (location: (0...3))
            ├── opening_loc: (0...2) = ":'"
            ├── value_loc: (2...2) = ""
            ├── closing_loc: (2...3) = "'"
            └── unescaped: ""
