@ ProgramNode (location: (0...20))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...20))
    └── body: (length: 2)
        ├── @ StringNode (location: (0...10))
        │   ├── opening_loc: (0...3) = "%q("
        │   ├── content_loc: (3...9) = "foobar"
        │   ├── closing_loc: (9...10) = ")"
        │   └── unescaped: "foobar"
        └── @ StringNode (location: (12...20))
            ├── opening_loc: (12...13) = "'"
            ├── content_loc: (13...19) = "foobar"
            ├── closing_loc: (19...20) = "'"
            └── unescaped: "foobar"
