code: def get_auth_class(authtype):
      if authtype is None:
          return None
      elif authtype.lower() == "none":
          return None
      elif authtype.lower() == "firebase":
          return FirebaseAuth
      elif authtype.lower() == "github":
          return GithubAuth
      else:
          raise ValueError(
              "Unknown authentication type {}, valid values are none, "
              + "firebase, github".format(authtype)
          )
  
imports: import os
  import getpass
  import time
  import json
  import shutil
  import atexit
  import tempfile
  import requests
  import re
  import uuid
  from builtins import input
  import google.auth.transport.requests
  import google.oauth2.id_token
  from studio.util.util import rand_string, check_for_kb_interrupt
  from studio import pyrebase
  from studio.util import logs
label_desc: Use image node_id 1 for calling a global function with example usage: get_auth_class(authtype) and returns: None, None, FirebaseAuth, GithubAuth