code: def register(cls, value_type):
      Box.types.add(cls)
      Box.type_mappings[value_type] = cls
      Box.type_mappings[cls] = cls
  
imports: import warnings
  from contextlib import contextmanager
  from collections import defaultdict
  from .util import subvals, toposort
  from .wrap_util import wraps
label_desc: Use image node_id 4 for calling the Box obj's underlying member method code with example usage: obj.register(cls, value_type) without return types