@ ProgramNode (location: (1,0)-(5,8))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(5,8))
    └── body: (length: 1)
        └── @ CallNode (location: (1,0)-(5,8))
            ├── flags: ∅
            ├── receiver:
            │   @ CallNode (location: (1,0)-(5,3))
            │   ├── flags: ignore_visibility
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── name: :proc
            │   ├── message_loc: (1,0)-(1,4) = "proc"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   └── block:
            │       @ BlockNode (location: (1,5)-(5,3))
            │       ├── locals: []
            │       ├── parameters: ∅
            │       ├── body:
            │       │   @ BeginNode (location: (1,5)-(5,3))
            │       │   ├── begin_keyword_loc: ∅
            │       │   ├── statements:
            │       │   │   @ StatementsNode (location: (2,2)-(2,8))
            │       │   │   └── body: (length: 1)
            │       │   │       └── @ SymbolNode (location: (2,2)-(2,8))
            │       │   │           ├── flags: forced_us_ascii_encoding
            │       │   │           ├── opening_loc: (2,2)-(2,3) = ":"
            │       │   │           ├── value_loc: (2,3)-(2,8) = "begin"
            │       │   │           ├── closing_loc: ∅
            │       │   │           └── unescaped: "begin"
            │       │   ├── rescue_clause: ∅
            │       │   ├── else_clause: ∅
            │       │   ├── ensure_clause:
            │       │   │   @ EnsureNode (location: (3,0)-(5,3))
            │       │   │   ├── ensure_keyword_loc: (3,0)-(3,6) = "ensure"
            │       │   │   ├── statements:
            │       │   │   │   @ StatementsNode (location: (4,2)-(4,9))
            │       │   │   │   └── body: (length: 1)
            │       │   │   │       └── @ SymbolNode (location: (4,2)-(4,9))
            │       │   │   │           ├── flags: forced_us_ascii_encoding
            │       │   │   │           ├── opening_loc: (4,2)-(4,3) = ":"
            │       │   │   │           ├── value_loc: (4,3)-(4,9) = "ensure"
            │       │   │   │           ├── closing_loc: ∅
            │       │   │   │           └── unescaped: "ensure"
            │       │   │   └── end_keyword_loc: (5,0)-(5,3) = "end"
            │       │   └── end_keyword_loc: (5,0)-(5,3) = "end"
            │       ├── opening_loc: (1,5)-(1,7) = "do"
            │       └── closing_loc: (5,0)-(5,3) = "end"
            ├── call_operator_loc: (5,3)-(5,4) = "."
            ├── name: :call
            ├── message_loc: (5,4)-(5,8) = "call"
            ├── opening_loc: ∅
            ├── arguments: ∅
            ├── closing_loc: ∅
            └── block: ∅
