@ ProgramNode (location: (0...17))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...17))
    └── body: (length: 1)
        └── @ CallNode (location: (0...17))
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── message_loc: (0...4) = "desc"
            ├── opening_loc: ∅
            ├── arguments:
            │   @ ArgumentsNode (location: (5...10))
            │   └── arguments: (length: 1)
            │       └── @ StringNode (location: (5...10))
            │           ├── opening_loc: (5...6) = "\""
            │           ├── content_loc: (6...9) = "foo"
            │           ├── closing_loc: (9...10) = "\""
            │           └── unescaped: "foo"
            ├── closing_loc: ∅
            ├── block:
            │   @ BlockNode (location: (11...17))
            │   ├── locals: []
            │   ├── parameters: ∅
            │   ├── body: ∅
            │   ├── opening_loc: (11...13) = "do"
            │   └── closing_loc: (14...17) = "end"
            ├── flags: ∅
            └── name: "desc"
