docs: def userinfo_in_id_token_claims(endpoint_context, session, def_itc=None):
      """
      Collect user info claims that are to be placed in the id token.
  
      :param endpoint_context: Endpoint context
      :param session: Session information
      :param def_itc: Default ID Token claims
      :return: User information or None
      """
      if def_itc:
          itc = def_itc
      else:
          itc = {}
  
      itc.update(id_token_claims(session))
  
      if not itc:
          return None
  
      _claims = by_schema(endpoint_context.id_token_schema, **itc)
  
      if _claims:
          return collect_user_info(endpoint_context, session, _claims)
      else:
          return None