@ ProgramNode (location: (0...9))
├── locals: [:a]
└── statements:
    @ StatementsNode (location: (0...9))
    └── body: (length: 1)
        └── @ LocalVariableWriteNode (location: (0...9))
            ├── name: :a
            ├── depth: 0
            ├── name_loc: (0...1) = "a"
            ├── value:
            │   @ CallNode (location: (4...9))
            │   ├── receiver:
            │   │   @ CallNode (location: (4...5))
            │   │   ├── receiver: ∅
            │   │   ├── call_operator_loc: ∅
            │   │   ├── message_loc: (4...5) = "b"
            │   │   ├── opening_loc: ∅
            │   │   ├── arguments: ∅
            │   │   ├── closing_loc: ∅
            │   │   ├── block: ∅
            │   │   ├── flags: variable_call
            │   │   └── name: "b"
            │   ├── call_operator_loc: (5...6) = "."
            │   ├── message_loc: (6...7) = "c"
            │   ├── opening_loc: ∅
            │   ├── arguments:
            │   │   @ ArgumentsNode (location: (8...9))
            │   │   └── arguments: (length: 1)
            │   │       └── @ IntegerNode (location: (8...9))
            │   │           └── flags: decimal
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: ∅
            │   └── name: "c"
            └── operator_loc: (2...3) = "="
