@ ProgramNode (location: (0...34))
├── locals: []
└── statements:
    @ StatementsNode (location: (0...34))
    └── body: (length: 1)
        └── @ CaseNode (location: (0...34))
            ├── predicate:
            │   @ CallNode (location: (5...8))
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── message_loc: (5...8) = "foo"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: variable_call
            │   └── name: "foo"
            ├── conditions: (length: 1)
            │   └── @ WhenNode (location: (10...29))
            │       ├── keyword_loc: (10...14) = "when"
            │       ├── conditions: (length: 1)
            │       │   └── @ StringNode (location: (15...20))
            │       │       ├── opening_loc: (15...16) = "'"
            │       │       ├── content_loc: (16...19) = "bar"
            │       │       ├── closing_loc: (19...20) = "'"
            │       │       └── unescaped: "bar"
            │       └── statements:
            │           @ StatementsNode (location: (26...29))
            │           └── body: (length: 1)
            │               └── @ CallNode (location: (26...29))
            │                   ├── receiver: ∅
            │                   ├── call_operator_loc: ∅
            │                   ├── message_loc: (26...29) = "bar"
            │                   ├── opening_loc: ∅
            │                   ├── arguments: ∅
            │                   ├── closing_loc: ∅
            │                   ├── block: ∅
            │                   ├── flags: variable_call
            │                   └── name: "bar"
            ├── consequent: ∅
            ├── case_keyword_loc: (0...4) = "case"
            └── end_keyword_loc: (31...34) = "end"
