@ ProgramNode (location: (1,0)-(1,4))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,4))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ RegularExpressionNode (location: (1,0)-(1,4))
            ├── flags: newline, static_literal, forced_us_ascii_encoding
            ├── opening_loc: (1,0)-(1,1) = "/"
            ├── content_loc: (1,1)-(1,3) = "\\("
            ├── closing_loc: (1,3)-(1,4) = "/"
            └── unescaped: "\\("
