@ ProgramNode (location: (1,0)-(1,4))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,4))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ StringNode (location: (1,0)-(1,4))
            ├── flags: newline
            ├── opening_loc: (1,0)-(1,4) = "<<~A"
            ├── content_loc: (2,0)-(3,0) = "a\n"
            ├── closing_loc: (3,0)-(4,0) = "A\n"
            └── unescaped: "a\n"
