class_docstr: An abstract visitor defined over Type.
  
  Defines the default dispatch over types.
code: def visit_ref_type(self, _):
      raise NotImplementedError()
  
imports: from .ty import TypeVar, IncompleteType, TensorType, FuncType, TupleType, TypeRelation, RefType, GlobalTypeVar, TypeCall
  from .adt import TypeData
label_desc: Use image node_id 9 for calling the TypeFunctor obj's underlying member method code with example usage: obj.visit_ref_type(_) without return types