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