@ ProgramNode (location: (1,0)-(1,20))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,20))
    └── body: (length: 1)
        └── @ CallNode (location: (1,0)-(1,20))
            ├── flags: ∅
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── name: :bl
            ├── message_loc: (1,0)-(1,2) = "bl"
            ├── opening_loc: ∅
            ├── arguments: ∅
            ├── closing_loc: ∅
            └── block:
                @ BlockNode (location: (1,3)-(1,20))
                ├── locals: [:kw]
                ├── locals_body_index: 1
                ├── parameters:
                │   @ BlockParametersNode (location: (1,5)-(1,15))
                │   ├── parameters:
                │   │   @ ParametersNode (location: (1,6)-(1,14))
                │   │   ├── requireds: (length: 0)
                │   │   ├── optionals: (length: 0)
                │   │   ├── rest: ∅
                │   │   ├── posts: (length: 0)
                │   │   ├── keywords: (length: 1)
                │   │   │   └── @ OptionalKeywordParameterNode (location: (1,6)-(1,14))
                │   │   │       ├── name: :kw
                │   │   │       ├── name_loc: (1,6)-(1,9) = "kw:"
                │   │   │       └── value:
                │   │   │           @ SymbolNode (location: (1,10)-(1,14))
                │   │   │           ├── flags: ∅
                │   │   │           ├── opening_loc: (1,10)-(1,11) = ":"
                │   │   │           ├── value_loc: (1,11)-(1,14) = "val"
                │   │   │           ├── closing_loc: ∅
                │   │   │           └── unescaped: "val"
                │   │   ├── keyword_rest: ∅
                │   │   └── block: ∅
                │   ├── locals: (length: 0)
                │   ├── opening_loc: (1,5)-(1,6) = "|"
                │   └── closing_loc: (1,14)-(1,15) = "|"
                ├── body:
                │   @ StatementsNode (location: (1,16)-(1,18))
                │   └── body: (length: 1)
                │       └── @ LocalVariableReadNode (location: (1,16)-(1,18))
                │           ├── name: :kw
                │           └── depth: 0
                ├── opening_loc: (1,3)-(1,4) = "{"
                └── closing_loc: (1,19)-(1,20) = "}"
