@ ProgramNode (location: (1,0)-(1,5))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,5))
    └── body: (length: 1)
        └── @ StringNode (location: (1,0)-(1,5))
            ├── flags: ∅
            ├── opening_loc: (1,0)-(1,5) = "<<EOS"
            ├── content_loc: (2,0)-(4,0) = "foo\\rbar\r\nbaz\\r\r\n"
            ├── closing_loc: (4,0)-(5,0) = "EOS\r\n"
            └── unescaped: "foo\rbar\r\nbaz\r\r\n"
