@ ProgramNode (location: (1,0)-(1,15))
├── flags: ∅
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,15))
    ├── flags: ∅
    └── body: (length: 1)
        └── @ ArrayNode (location: (1,0)-(1,15))
            ├── flags: newline
            ├── elements: (length: 3)
            │   ├── @ SymbolNode (location: (1,3)-(1,4))
            │   │   ├── flags: static_literal, forced_us_ascii_encoding
            │   │   ├── opening_loc: ∅
            │   │   ├── value_loc: (1,3)-(1,4) = "a"
            │   │   ├── closing_loc: ∅
            │   │   └── unescaped: "a"
            │   ├── @ InterpolatedSymbolNode (location: (1,5)-(1,12))
            │   │   ├── flags: ∅
            │   │   ├── opening_loc: ∅
            │   │   ├── parts: (length: 2)
            │   │   │   ├── @ StringNode (location: (1,5)-(1,6))
            │   │   │   │   ├── flags: static_literal, frozen
            │   │   │   │   ├── opening_loc: ∅
            │   │   │   │   ├── content_loc: (1,5)-(1,6) = "b"
            │   │   │   │   ├── closing_loc: ∅
            │   │   │   │   └── unescaped: "b"
            │   │   │   └── @ EmbeddedStatementsNode (location: (1,6)-(1,12))
            │   │   │       ├── flags: ∅
            │   │   │       ├── opening_loc: (1,6)-(1,8) = "\#{"
            │   │   │       ├── statements:
            │   │   │       │   @ StatementsNode (location: (1,8)-(1,11))
            │   │   │       │   ├── flags: ∅
            │   │   │       │   └── body: (length: 1)
            │   │   │       │       └── @ CallNode (location: (1,8)-(1,11))
            │   │   │       │           ├── flags: ∅
            │   │   │       │           ├── receiver:
            │   │   │       │           │   @ IntegerNode (location: (1,8)-(1,9))
            │   │   │       │           │   ├── flags: static_literal, decimal
            │   │   │       │           │   └── value: 1
            │   │   │       │           ├── call_operator_loc: ∅
            │   │   │       │           ├── name: :+
            │   │   │       │           ├── message_loc: (1,9)-(1,10) = "+"
            │   │   │       │           ├── opening_loc: ∅
            │   │   │       │           ├── arguments:
            │   │   │       │           │   @ ArgumentsNode (location: (1,10)-(1,11))
            │   │   │       │           │   ├── flags: ∅
            │   │   │       │           │   └── arguments: (length: 1)
            │   │   │       │           │       └── @ IntegerNode (location: (1,10)-(1,11))
            │   │   │       │           │           ├── flags: static_literal, decimal
            │   │   │       │           │           └── value: 1
            │   │   │       │           ├── closing_loc: ∅
            │   │   │       │           ├── equal_loc: ∅
            │   │   │       │           └── block: ∅
            │   │   │       └── closing_loc: (1,11)-(1,12) = "}"
            │   │   └── closing_loc: ∅
            │   └── @ SymbolNode (location: (1,13)-(1,14))
            │       ├── flags: static_literal, forced_us_ascii_encoding
            │       ├── opening_loc: ∅
            │       ├── value_loc: (1,13)-(1,14) = "c"
            │       ├── closing_loc: ∅
            │       └── unescaped: "c"
            ├── opening_loc: (1,0)-(1,3) = "%I("
            └── closing_loc: (1,14)-(1,15) = ")"
