@ ProgramNode (location: (1,0)-(1,20))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,20))
    └── body: (length: 1)
        └── @ BreakNode (location: (1,0)-(1,20))
            ├── arguments:
            │   @ ArgumentsNode (location: (1,6)-(1,20))
            │   ├── flags: ∅
            │   └── arguments: (length: 1)
            │       └── @ CallNode (location: (1,6)-(1,20))
            │           ├── flags: ∅
            │           ├── receiver: ∅
            │           ├── call_operator_loc: ∅
            │           ├── name: :fun
            │           ├── message_loc: (1,6)-(1,9) = "fun"
            │           ├── opening_loc: ∅
            │           ├── arguments:
            │           │   @ ArgumentsNode (location: (1,10)-(1,13))
            │           │   ├── flags: ∅
            │           │   └── arguments: (length: 1)
            │           │       └── @ CallNode (location: (1,10)-(1,13))
            │           │           ├── flags: variable_call
            │           │           ├── receiver: ∅
            │           │           ├── call_operator_loc: ∅
            │           │           ├── name: :foo
            │           │           ├── message_loc: (1,10)-(1,13) = "foo"
            │           │           ├── opening_loc: ∅
            │           │           ├── arguments: ∅
            │           │           ├── closing_loc: ∅
            │           │           └── block: ∅
            │           ├── closing_loc: ∅
            │           └── block:
            │               @ BlockNode (location: (1,14)-(1,20))
            │               ├── locals: []
            │               ├── locals_body_index: 0
            │               ├── parameters: ∅
            │               ├── body: ∅
            │               ├── opening_loc: (1,14)-(1,16) = "do"
            │               └── closing_loc: (1,17)-(1,20) = "end"
            └── keyword_loc: (1,0)-(1,5) = "break"
