@ ProgramNode (location: (1,0)-(2,3))
├── locals: []
└── statements:
    @ StatementsNode (location: (1,0)-(2,3))
    └── body: (length: 1)
        └── @ ClassNode (location: (1,0)-(2,3))
            ├── locals: []
            ├── class_keyword_loc: (1,0)-(1,5) = "class"
            ├── constant_path:
            │   @ ConstantReadNode (location: (1,6)-(1,7))
            │   └── name: :A
            ├── inheritance_operator_loc: (1,8)-(1,9) = "<"
            ├── superclass:
            │   @ ConstantReadNode (location: (1,10)-(1,11))
            │   └── name: :B
            ├── body: ∅
            ├── end_keyword_loc: (2,0)-(2,3) = "end"
            └── name: :A