@ ProgramNode (location: (1,0)-(3,3))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(3,3))
    └── body: (length: 1)
        └── @ BeginNode (location: (1,0)-(3,3))
            ├── begin_keyword_loc: (1,0)-(1,5) = "begin"
            ├── statements: ∅
            ├── rescue_clause: ∅
            ├── else_clause: ∅
            ├── ensure_clause:
            │   @ EnsureNode (location: (2,0)-(3,3))
            │   ├── ensure_keyword_loc: (2,0)-(2,6) = "ensure"
            │   ├── statements: ∅
            │   └── end_keyword_loc: (3,0)-(3,3) = "end"
            └── end_keyword_loc: (3,0)-(3,3) = "end"