@ ProgramNode (location: (1,0)-(1,26))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,26))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ CaseNode (location: (1,0)-(1,26))
            ├── flags: newline
            ├── predicate:
            │   @ SymbolNode (location: (1,5)-(1,7))
            │   ├── flags: static_literal, forced_us_ascii_encoding
            │   ├── opening_loc: (1,5)-(1,6) = ":"
            │   ├── value_loc: (1,6)-(1,7) = "x"
            │   ├── closing_loc: ∅
            │   └── unescaped: "x"
            ├── conditions: (length: 1)
            │   └── @ WhenNode (location: (1,9)-(1,22))
            │       ├── flags: ∅
            │       ├── keyword_loc: (1,9)-(1,13) = "when"
            │       ├── conditions: (length: 1)
            │       │   └── @ RegularExpressionNode (location: (1,14)-(1,17))
            │       │       ├── flags: static_literal, forced_us_ascii_encoding
            │       │       ├── opening_loc: (1,14)-(1,15) = "/"
            │       │       ├── content_loc: (1,15)-(1,16) = "x"
            │       │       ├── closing_loc: (1,16)-(1,17) = "/"
            │       │       └── unescaped: "x"
            │       ├── then_keyword_loc: (1,18)-(1,22) = "then"
            │       └── statements: ∅
            ├── else_clause: ∅
            ├── case_keyword_loc: (1,0)-(1,4) = "case"
            └── end_keyword_loc: (1,23)-(1,26) = "end"
