@ ProgramNode (location: (1,0)-(1,4))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,4))
    └── body: (length: 1)
        └── @ InterpolatedStringNode (location: (1,0)-(1,4))
            ├── opening_loc: (1,0)-(1,4) = "<<\"\""
            ├── parts: (length: 2)
            │   ├── @ EmbeddedStatementsNode (location: (2,0)-(2,4))
            │   │   ├── opening_loc: (2,0)-(2,2) = "\#{"
            │   │   ├── statements:
            │   │   │   @ StatementsNode (location: (2,2)-(2,3))
            │   │   │   └── body: (length: 1)
            │   │   │       └── @ CallNode (location: (2,2)-(2,3))
            │   │   │           ├── flags: variable_call, ignore_visibility
            │   │   │           ├── receiver: ∅
            │   │   │           ├── call_operator_loc: ∅
            │   │   │           ├── name: :x
            │   │   │           ├── message_loc: (2,2)-(2,3) = "x"
            │   │   │           ├── opening_loc: ∅
            │   │   │           ├── arguments: ∅
            │   │   │           ├── closing_loc: ∅
            │   │   │           └── block: ∅
            │   │   └── closing_loc: (2,3)-(2,4) = "}"
            │   └── @ StringNode (location: (2,4)-(4,0))
            │       ├── flags: ∅
            │       ├── opening_loc: ∅
            │       ├── content_loc: (2,4)-(4,0) = "\nblah2\n"
            │       ├── closing_loc: ∅
            │       └── unescaped: "\nblah2\n"
            └── closing_loc: (4,0)-(5,0) = "\n"
