@ ProgramNode (location: (1,0)-(6,5))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(6,5))
    └── body: (length: 2)
        ├── @ CallNode (location: (1,0)-(4,8))
        │   ├── receiver: ∅
        │   ├── call_operator_loc: ∅
        │   ├── message_loc: (1,0)-(1,4) = "puts"
        │   ├── opening_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (1,5)-(4,8))
        │   │   ├── arguments: (length: 1)
        │   │   │   └── @ StringNode (location: (1,5)-(4,8))
        │   │   │       ├── flags: ∅
        │   │   │       ├── opening_loc: (1,5)-(1,6) = "\""
        │   │   │       ├── content_loc: (1,6)-(4,7) = "hello\\\n my\\\n dear\\\n friend"
        │   │   │       ├── closing_loc: (4,7)-(4,8) = "\""
        │   │   │       └── unescaped: "hello my dear friend"
        │   │   └── flags: ∅
        │   ├── closing_loc: ∅
        │   ├── block: ∅
        │   ├── flags: ∅
        │   └── name: :puts
        └── @ CallNode (location: (6,0)-(6,5))
            ├── receiver:
            │   @ CallNode (location: (6,0)-(6,1))
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── message_loc: (6,0)-(6,1) = "a"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: variable_call
            │   └── name: :a
            ├── call_operator_loc: ∅
            ├── message_loc: (6,2)-(6,3) = "+"
            ├── opening_loc: ∅
            ├── arguments:
            │   @ ArgumentsNode (location: (6,4)-(6,5))
            │   ├── arguments: (length: 1)
            │   │   └── @ CallNode (location: (6,4)-(6,5))
            │   │       ├── receiver: ∅
            │   │       ├── call_operator_loc: ∅
            │   │       ├── message_loc: (6,4)-(6,5) = "b"
            │   │       ├── opening_loc: ∅
            │   │       ├── arguments: ∅
            │   │       ├── closing_loc: ∅
            │   │       ├── block: ∅
            │   │       ├── flags: variable_call
            │   │       └── name: :b
            │   └── flags: ∅
            ├── closing_loc: ∅
            ├── block: ∅
            ├── flags: ∅
            └── name: :+
