@ ProgramNode (location: (1,0)-(3,15))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(3,15))
    └── body: (length: 2)
        ├── @ CallNode (location: (1,0)-(1,14))
        │   ├── flags: ignore_visibility
        │   ├── receiver: ∅
        │   ├── call_operator_loc: ∅
        │   ├── name: :foo
        │   ├── message_loc: (1,0)-(1,3) = "foo"
        │   ├── opening_loc: ∅
        │   ├── arguments:
        │   │   @ ArgumentsNode (location: (1,4)-(1,14))
        │   │   ├── flags: ∅
        │   │   └── arguments: (length: 1)
        │   │       └── @ CallNode (location: (1,4)-(1,14))
        │   │           ├── flags: ∅
        │   │           ├── receiver:
        │   │           │   @ ParenthesesNode (location: (1,4)-(1,10))
        │   │           │   ├── body:
        │   │           │   │   @ StatementsNode (location: (1,5)-(1,9))
        │   │           │   │   └── body: (length: 1)
        │   │           │   │       └── @ FloatNode (location: (1,5)-(1,9))
        │   │           │   ├── opening_loc: (1,4)-(1,5) = "("
        │   │           │   └── closing_loc: (1,9)-(1,10) = ")"
        │   │           ├── call_operator_loc: (1,10)-(1,11) = "."
        │   │           ├── name: :abs
        │   │           ├── message_loc: (1,11)-(1,14) = "abs"
        │   │           ├── opening_loc: ∅
        │   │           ├── arguments: ∅
        │   │           ├── closing_loc: ∅
        │   │           └── block: ∅
        │   ├── closing_loc: ∅
        │   └── block: ∅
        └── @ CallNode (location: (3,0)-(3,15))
            ├── flags: ignore_visibility
            ├── receiver: ∅
            ├── call_operator_loc: ∅
            ├── name: :meth
            ├── message_loc: (3,0)-(3,4) = "meth"
            ├── opening_loc: ∅
            ├── arguments:
            │   @ ArgumentsNode (location: (3,5)-(3,15))
            │   ├── flags: ∅
            │   └── arguments: (length: 1)
            │       └── @ CallNode (location: (3,5)-(3,15))
            │           ├── flags: ∅
            │           ├── receiver:
            │           │   @ ParenthesesNode (location: (3,5)-(3,11))
            │           │   ├── body:
            │           │   │   @ StatementsNode (location: (3,6)-(3,10))
            │           │   │   └── body: (length: 1)
            │           │   │       └── @ FloatNode (location: (3,6)-(3,10))
            │           │   ├── opening_loc: (3,5)-(3,6) = "("
            │           │   └── closing_loc: (3,10)-(3,11) = ")"
            │           ├── call_operator_loc: (3,11)-(3,12) = "."
            │           ├── name: :abs
            │           ├── message_loc: (3,12)-(3,15) = "abs"
            │           ├── opening_loc: ∅
            │           ├── arguments: ∅
            │           ├── closing_loc: ∅
            │           └── block: ∅
            ├── closing_loc: ∅
            └── block: ∅
