@ ProgramNode (location: (0...14))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...14))
    └── body: (length: 2)
        ├── @ InterpolatedStringNode (location: (0...9))
        │   ├── opening_loc: (0...1) = "\""
        │   ├── parts: (length: 2)
        │   │   ├── @ StringNode (location: (1...4))
        │   │   │   ├── opening_loc: ∅
        │   │   │   ├── content_loc: (1...4) = "a\\n"
        │   │   │   ├── closing_loc: ∅
        │   │   │   └── unescaped: "a\n"
        │   │   └── @ EmbeddedStatementsNode (location: (4...8))
        │   │       ├── opening_loc: (4...6) = "\#{"
        │   │       ├── statements: ∅
        │   │       └── closing_loc: (7...8) = "}"
        │   └── closing_loc: (8...9) = "\""
        └── @ TrueNode (location: (10...14))
