@ ProgramNode (location: (1,0)-(3,8))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(3,8))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ CallNode (location: (1,0)-(3,8))
            ├── flags: newline, attribute_write
            ├── receiver:
            │   @ CallNode (location: (1,0)-(1,1))
            │   ├── flags: variable_call, ignore_visibility
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── name: :h
            │   ├── message_loc: (1,0)-(1,1) = "h"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   └── block: ∅
            ├── call_operator_loc: ∅
            ├── name: :[]=
            ├── message_loc: (1,1)-(1,4) = "[k]"
            ├── opening_loc: (1,1)-(1,2) = "["
            ├── arguments:
            │   @ ArgumentsNode (location: (1,2)-(3,8))
            │   ├── flags: ∅
            │   └── arguments: (length: 2)
            │       ├── @ CallNode (location: (1,2)-(1,3))
            │       │   ├── flags: variable_call, ignore_visibility
            │       │   ├── receiver: ∅
            │       │   ├── call_operator_loc: ∅
            │       │   ├── name: :k
            │       │   ├── message_loc: (1,2)-(1,3) = "k"
            │       │   ├── opening_loc: ∅
            │       │   ├── arguments: ∅
            │       │   ├── closing_loc: ∅
            │       │   └── block: ∅
            │       └── @ BeginNode (location: (1,5)-(3,8))
            │           ├── flags: ∅
            │           ├── begin_keyword_loc: (1,5)-(1,10) = "begin"
            │           ├── statements:
            │           │   @ StatementsNode (location: (2,7)-(2,9))
            │           │   ├── flags: ∅
            │           │   └── body: (length: 1)
            │           │       └── @ IntegerNode (location: (2,7)-(2,9))
            │           │           ├── flags: newline, static_literal, decimal
            │           │           └── value: 42
            │           ├── rescue_clause: ∅
            │           ├── else_clause: ∅
            │           ├── ensure_clause: ∅
            │           └── end_keyword_loc: (3,5)-(3,8) = "end"
            ├── closing_loc: (1,3)-(1,4) = "]"
            └── block: ∅
