@ ProgramNode (location: (1,0)-(5,4))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(5,4))
    └── body: (length: 1)
        └── @ CallNode (location: (1,0)-(5,4))
            ├── flags: ignore_visibility
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── name: :a
            ├── message_loc: (1,0)-(1,1) = "a"
            ├── opening_loc: (1,1)-(1,2) = "("
            ├── arguments:
            │   @ ArgumentsNode (location: (1,2)-(5,3))
            │   ├── flags: ∅
            │   └── arguments: (length: 1)
            │       └── @ KeywordHashNode (location: (1,2)-(5,3))
            │           ├── flags: symbol_keys
            │           └── elements: (length: 1)
            │               └── @ AssocNode (location: (1,2)-(5,3))
            │                   ├── key:
            │                   │   @ SymbolNode (location: (1,2)-(1,4))
            │                   │   ├── flags: forced_us_ascii_encoding
            │                   │   ├── opening_loc: ∅
            │                   │   ├── value_loc: (1,2)-(1,3) = "b"
            │                   │   ├── closing_loc: (1,3)-(1,4) = ":"
            │                   │   └── unescaped: "b"
            │                   ├── value:
            │                   │   @ IfNode (location: (1,5)-(5,3))
            │                   │   ├── if_keyword_loc: (1,5)-(1,7) = "if"
            │                   │   ├── predicate:
            │                   │   │   @ SymbolNode (location: (1,8)-(1,10))
            │                   │   │   ├── flags: forced_us_ascii_encoding
            │                   │   │   ├── opening_loc: (1,8)-(1,9) = ":"
            │                   │   │   ├── value_loc: (1,9)-(1,10) = "c"
            │                   │   │   ├── closing_loc: ∅
            │                   │   │   └── unescaped: "c"
            │                   │   ├── then_keyword_loc: ∅
            │                   │   ├── statements:
            │                   │   │   @ StatementsNode (location: (2,0)-(2,1))
            │                   │   │   └── body: (length: 1)
            │                   │   │       └── @ IntegerNode (location: (2,0)-(2,1))
            │                   │   │           ├── flags: decimal
            │                   │   │           └── value: 1
            │                   │   ├── consequent:
            │                   │   │   @ ElseNode (location: (3,0)-(5,3))
            │                   │   │   ├── else_keyword_loc: (3,0)-(3,4) = "else"
            │                   │   │   ├── statements:
            │                   │   │   │   @ StatementsNode (location: (4,0)-(4,1))
            │                   │   │   │   └── body: (length: 1)
            │                   │   │   │       └── @ IntegerNode (location: (4,0)-(4,1))
            │                   │   │   │           ├── flags: decimal
            │                   │   │   │           └── value: 2
            │                   │   │   └── end_keyword_loc: (5,0)-(5,3) = "end"
            │                   │   └── end_keyword_loc: (5,0)-(5,3) = "end"
            │                   └── operator_loc: ∅
            ├── closing_loc: (5,3)-(5,4) = ")"
            └── block: ∅