@ ProgramNode (location: (1,0)-(3,4))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(3,4))
    └── body: (length: 2)
        ├── @ SymbolNode (location: (1,0)-(1,6))
        │   ├── flags: forced_us_ascii_encoding
        │   ├── opening_loc: (1,0)-(1,2) = ":'"
        │   ├── value_loc: (1,2)-(1,5) = "foo"
        │   ├── closing_loc: (1,5)-(1,6) = "'"
        │   └── unescaped: "foo"
        └── @ SymbolNode (location: (3,0)-(3,4))
            ├── flags: forced_us_ascii_encoding
            ├── opening_loc: (3,0)-(3,1) = ":"
            ├── value_loc: (3,1)-(3,4) = "foo"
            ├── closing_loc: ∅
            └── unescaped: "foo"