@ ProgramNode (location: (1,0)-(7,22))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(7,22))
    └── body: (length: 4)
        ├── @ DefNode (location: (1,0)-(1,14))
        │   ├── name: :foo
        │   ├── name_loc: (1,4)-(1,7) = "foo"
        │   ├── receiver: ∅
        │   ├── parameters: ∅
        │   ├── body:
        │   │   @ StatementsNode (location: (1,12)-(1,14))
        │   │   └── body: (length: 1)
        │   │       └── @ IntegerNode (location: (1,12)-(1,14))
        │   │           └── flags: decimal
        │   ├── locals: []
        │   ├── def_keyword_loc: (1,0)-(1,3) = "def"
        │   ├── operator_loc: ∅
        │   ├── lparen_loc: (1,7)-(1,8) = "("
        │   ├── rparen_loc: (1,8)-(1,9) = ")"
        │   ├── equal_loc: (1,10)-(1,11) = "="
        │   └── end_keyword_loc: ∅
        ├── @ DefNode (location: (3,0)-(3,18))
        │   ├── name: :inc
        │   ├── name_loc: (3,4)-(3,7) = "inc"
        │   ├── receiver: ∅
        │   ├── parameters:
        │   │   @ ParametersNode (location: (3,8)-(3,9))
        │   │   ├── requireds: (length: 1)
        │   │   │   └── @ RequiredParameterNode (location: (3,8)-(3,9))
        │   │   │       └── name: :x
        │   │   ├── optionals: (length: 0)
        │   │   ├── rest: ∅
        │   │   ├── posts: (length: 0)
        │   │   ├── keywords: (length: 0)
        │   │   ├── keyword_rest: ∅
        │   │   └── block: ∅
        │   ├── body:
        │   │   @ StatementsNode (location: (3,13)-(3,18))
        │   │   └── body: (length: 1)
        │   │       └── @ CallNode (location: (3,13)-(3,18))
        │   │           ├── receiver:
        │   │           │   @ LocalVariableReadNode (location: (3,13)-(3,14))
        │   │           │   ├── name: :x
        │   │           │   └── depth: 0
        │   │           ├── call_operator_loc: ∅
        │   │           ├── message_loc: (3,15)-(3,16) = "+"
        │   │           ├── opening_loc: ∅
        │   │           ├── arguments:
        │   │           │   @ ArgumentsNode (location: (3,17)-(3,18))
        │   │           │   ├── arguments: (length: 1)
        │   │           │   │   └── @ IntegerNode (location: (3,17)-(3,18))
        │   │           │   │       └── flags: decimal
        │   │           │   └── flags: ∅
        │   │           ├── closing_loc: ∅
        │   │           ├── block: ∅
        │   │           ├── flags: ∅
        │   │           └── name: :+
        │   ├── locals: [:x]
        │   ├── def_keyword_loc: (3,0)-(3,3) = "def"
        │   ├── operator_loc: ∅
        │   ├── lparen_loc: (3,7)-(3,8) = "("
        │   ├── rparen_loc: (3,9)-(3,10) = ")"
        │   ├── equal_loc: (3,11)-(3,12) = "="
        │   └── end_keyword_loc: ∅
        ├── @ DefNode (location: (5,0)-(5,18))
        │   ├── name: :foo
        │   ├── name_loc: (5,8)-(5,11) = "foo"
        │   ├── receiver:
        │   │   @ CallNode (location: (5,4)-(5,7))
        │   │   ├── receiver: ∅
        │   │   ├── call_operator_loc: ∅
        │   │   ├── message_loc: (5,4)-(5,7) = "obj"
        │   │   ├── opening_loc: ∅
        │   │   ├── arguments: ∅
        │   │   ├── closing_loc: ∅
        │   │   ├── block: ∅
        │   │   ├── flags: variable_call
        │   │   └── name: :obj
        │   ├── parameters: ∅
        │   ├── body:
        │   │   @ StatementsNode (location: (5,16)-(5,18))
        │   │   └── body: (length: 1)
        │   │       └── @ IntegerNode (location: (5,16)-(5,18))
        │   │           └── flags: decimal
        │   ├── locals: []
        │   ├── def_keyword_loc: (5,0)-(5,3) = "def"
        │   ├── operator_loc: (5,7)-(5,8) = "."
        │   ├── lparen_loc: (5,11)-(5,12) = "("
        │   ├── rparen_loc: (5,12)-(5,13) = ")"
        │   ├── equal_loc: (5,14)-(5,15) = "="
        │   └── end_keyword_loc: ∅
        └── @ DefNode (location: (7,0)-(7,22))
            ├── name: :inc
            ├── name_loc: (7,8)-(7,11) = "inc"
            ├── receiver:
            │   @ CallNode (location: (7,4)-(7,7))
            │   ├── receiver: ∅
            │   ├── call_operator_loc: ∅
            │   ├── message_loc: (7,4)-(7,7) = "obj"
            │   ├── opening_loc: ∅
            │   ├── arguments: ∅
            │   ├── closing_loc: ∅
            │   ├── block: ∅
            │   ├── flags: variable_call
            │   └── name: :obj
            ├── parameters:
            │   @ ParametersNode (location: (7,12)-(7,13))
            │   ├── requireds: (length: 1)
            │   │   └── @ RequiredParameterNode (location: (7,12)-(7,13))
            │   │       └── name: :x
            │   ├── optionals: (length: 0)
            │   ├── rest: ∅
            │   ├── posts: (length: 0)
            │   ├── keywords: (length: 0)
            │   ├── keyword_rest: ∅
            │   └── block: ∅
            ├── body:
            │   @ StatementsNode (location: (7,17)-(7,22))
            │   └── body: (length: 1)
            │       └── @ CallNode (location: (7,17)-(7,22))
            │           ├── receiver:
            │           │   @ LocalVariableReadNode (location: (7,17)-(7,18))
            │           │   ├── name: :x
            │           │   └── depth: 0
            │           ├── call_operator_loc: ∅
            │           ├── message_loc: (7,19)-(7,20) = "+"
            │           ├── opening_loc: ∅
            │           ├── arguments:
            │           │   @ ArgumentsNode (location: (7,21)-(7,22))
            │           │   ├── arguments: (length: 1)
            │           │   │   └── @ IntegerNode (location: (7,21)-(7,22))
            │           │   │       └── flags: decimal
            │           │   └── flags: ∅
            │           ├── closing_loc: ∅
            │           ├── block: ∅
            │           ├── flags: ∅
            │           └── name: :+
            ├── locals: [:x]
            ├── def_keyword_loc: (7,0)-(7,3) = "def"
            ├── operator_loc: (7,7)-(7,8) = "."
            ├── lparen_loc: (7,11)-(7,12) = "("
            ├── rparen_loc: (7,13)-(7,14) = ")"
            ├── equal_loc: (7,15)-(7,16) = "="
            └── end_keyword_loc: ∅
