@ ProgramNode (location: (1,0)-(5,10))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(5,10))
    ├── flags: ∅
    └── body: (length: 3)
        ├── @ CallNode (location: (1,0)-(1,14))
        │   ├── flags: newline
        │   ├── receiver:
        │   │   @ CallNode (location: (1,0)-(1,3))
        │   │   ├── flags: variable_call, ignore_visibility
        │   │   ├── receiver: ∅
        │   │   ├── call_operator_loc: ∅
        │   │   ├── name: :foo
        │   │   ├── message_loc: (1,0)-(1,3) = "foo"
        │   │   ├── opening_loc: ∅
        │   │   ├── arguments: ∅
        │   │   ├── closing_loc: ∅
        │   │   ├── equal_loc: ∅
        │   │   └── block: ∅
        │   ├── call_operator_loc: (1,3)-(1,4) = "."
        │   ├── name: :fun
        │   ├── message_loc: (1,4)-(1,7) = "fun"
        │   ├── opening_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (1,8)-(1,11))
        │   │   ├── flags: ∅
        │   │   └── arguments: (length: 1)
        │   │       └── @ ParenthesesNode (location: (1,8)-(1,11))
        │   │           ├── flags: ∅
        │   │           ├── body:
        │   │           │   @ StatementsNode (location: (1,9)-(1,10))
        │   │           │   ├── flags: ∅
        │   │           │   └── body: (length: 1)
        │   │           │       └── @ IntegerNode (location: (1,9)-(1,10))
        │   │           │           ├── flags: newline, static_literal, decimal
        │   │           │           └── value: 1
        │   │           ├── opening_loc: (1,8)-(1,9) = "("
        │   │           └── closing_loc: (1,10)-(1,11) = ")"
        │   ├── closing_loc: ∅
        │   ├── equal_loc: ∅
        │   └── block:
        │       @ BlockNode (location: (1,12)-(1,14))
        │       ├── flags: ∅
        │       ├── locals: []
        │       ├── parameters: ∅
        │       ├── body: ∅
        │       ├── opening_loc: (1,12)-(1,13) = "{"
        │       └── closing_loc: (1,13)-(1,14) = "}"
        ├── @ CallNode (location: (3,0)-(3,15))
        │   ├── flags: newline
        │   ├── receiver:
        │   │   @ CallNode (location: (3,0)-(3,3))
        │   │   ├── flags: variable_call, ignore_visibility
        │   │   ├── receiver: ∅
        │   │   ├── call_operator_loc: ∅
        │   │   ├── name: :foo
        │   │   ├── message_loc: (3,0)-(3,3) = "foo"
        │   │   ├── opening_loc: ∅
        │   │   ├── arguments: ∅
        │   │   ├── closing_loc: ∅
        │   │   ├── equal_loc: ∅
        │   │   └── block: ∅
        │   ├── call_operator_loc: (3,3)-(3,5) = "::"
        │   ├── name: :fun
        │   ├── message_loc: (3,5)-(3,8) = "fun"
        │   ├── opening_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (3,9)-(3,12))
        │   │   ├── flags: ∅
        │   │   └── arguments: (length: 1)
        │   │       └── @ ParenthesesNode (location: (3,9)-(3,12))
        │   │           ├── flags: ∅
        │   │           ├── body:
        │   │           │   @ StatementsNode (location: (3,10)-(3,11))
        │   │           │   ├── flags: ∅
        │   │           │   └── body: (length: 1)
        │   │           │       └── @ IntegerNode (location: (3,10)-(3,11))
        │   │           │           ├── flags: newline, static_literal, decimal
        │   │           │           └── value: 1
        │   │           ├── opening_loc: (3,9)-(3,10) = "("
        │   │           └── closing_loc: (3,11)-(3,12) = ")"
        │   ├── closing_loc: ∅
        │   ├── equal_loc: ∅
        │   └── block:
        │       @ BlockNode (location: (3,13)-(3,15))
        │       ├── flags: ∅
        │       ├── locals: []
        │       ├── parameters: ∅
        │       ├── body: ∅
        │       ├── opening_loc: (3,13)-(3,14) = "{"
        │       └── closing_loc: (3,14)-(3,15) = "}"
        └── @ CallNode (location: (5,0)-(5,10))
            ├── flags: newline, ignore_visibility
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── name: :fun
            ├── message_loc: (5,0)-(5,3) = "fun"
            ├── opening_loc: ∅
            ├── arguments:
            │   @ ArgumentsNode (location: (5,4)-(5,7))
            │   ├── flags: ∅
            │   └── arguments: (length: 1)
            │       └── @ ParenthesesNode (location: (5,4)-(5,7))
            │           ├── flags: ∅
            │           ├── body:
            │           │   @ StatementsNode (location: (5,5)-(5,6))
            │           │   ├── flags: ∅
            │           │   └── body: (length: 1)
            │           │       └── @ IntegerNode (location: (5,5)-(5,6))
            │           │           ├── flags: newline, static_literal, decimal
            │           │           └── value: 1
            │           ├── opening_loc: (5,4)-(5,5) = "("
            │           └── closing_loc: (5,6)-(5,7) = ")"
            ├── closing_loc: ∅
            ├── equal_loc: ∅
            └── block:
                @ BlockNode (location: (5,8)-(5,10))
                ├── flags: ∅
                ├── locals: []
                ├── parameters: ∅
                ├── body: ∅
                ├── opening_loc: (5,8)-(5,9) = "{"
                └── closing_loc: (5,9)-(5,10) = "}"
