@ ProgramNode (location: (0...5))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...5))
    └── body: (length: 1)
        └── @ StringNode (location: (0...5))
            ├── opening_loc: (0...5) = "<<EOS"
            ├── content_loc: (6...21) = "foo\\rbar\nbaz\\r\n"
            ├── closing_loc: (21...25) = "EOS\n"
            └── unescaped: "foo\rbar\nbaz\r\n"
