code: def _validate_class_name(proposed_class_name):
      """Used to validate class names before registration.
  
      Attributes:
          proposed_class_name: The string to name the class.
      """
      # regex for class name came from
      # https://stackoverflow.com/questions/10120295
      # TODO: Support other languages
      match = re.match(r"[a-zA-Z_][a-zA-Z_0-9]+", proposed_class_name)
      if match is None or match.group(0) != proposed_class_name:
          raise ValueError(
              "Invalid class name {}. Class names must start with a "
              "letter or an underscore and can continue with letters, "
              "numbers, and underscores.".format(proposed_class_name)
          )
  
file_path: interpret/python/interpret-core/interpret/ext/extension_utils.py
imports: import sys
  import logging
  from importlib.metadata import entry_points
  import re
  from warnings import warn
  import traceback
label_desc: Use image node_id 1 for calling a global function with example usage: _validate_class_name(proposed_class_name) without return types