@ ProgramNode (location: (1,0)-(1,6))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,6))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ RegularExpressionNode (location: (1,0)-(1,6))
            ├── flags: newline, static_literal, forced_us_ascii_encoding
            ├── opening_loc: (1,0)-(1,3) = "%r'"
            ├── content_loc: (1,3)-(1,5) = "\\'"
            ├── closing_loc: (1,5)-(1,6) = "'"
            └── unescaped: "'"
