@ ProgramNode (location: (1,0)-(1,8))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(1,8))
    └── body: (length: 1)
        └── @ CallNode (location: (1,0)-(1,8))
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── message_loc: (1,0)-(1,1) = "x"
            ├── opening_loc: ∅
            ├── arguments:
            │   @ ArgumentsNode (location: (1,2)-(1,8))
            │   └── arguments: (length: 1)
            │       └── @ InterpolatedXStringNode (location: (1,2)-(1,8))
            │           ├── opening_loc: (1,2)-(1,3) = "`"
            │           ├── parts: (length: 1)
            │           │   └── @ EmbeddedStatementsNode (location: (1,3)-(1,7))
            │           │       ├── opening_loc: (1,3)-(1,5) = "\#{"
            │           │       ├── statements:
            │           │       │   @ StatementsNode (location: (1,5)-(1,6))
            │           │       │   └── body: (length: 1)
            │           │       │       └── @ CallNode (location: (1,5)-(1,6))
            │           │       │           ├── receiver: ∅
            │           │       │           ├── call_operator_loc: ∅
            │           │       │           ├── message_loc: (1,5)-(1,6) = "y"
            │           │       │           ├── opening_loc: ∅
            │           │       │           ├── arguments: ∅
            │           │       │           ├── closing_loc: ∅
            │           │       │           ├── block: ∅
            │           │       │           ├── flags: variable_call
            │           │       │           └── name: "y"
            │           │       └── closing_loc: (1,6)-(1,7) = "}"
            │           └── closing_loc: (1,7)-(1,8) = "`"
            ├── closing_loc: ∅
            ├── block: ∅
            ├── flags: ∅
            └── name: "x"