code: def has_duplicate_keys(config_data, base_conf, raise_error):
      
      duplicate_keys = set(base_conf) & set(config_data)
      if not duplicate_keys:
          return
      msg = "Duplicate keys in config: %s" % duplicate_keys
      if raise_error:
          raise errors.ConfigurationError(msg)
      log.info(msg)
      return True
docs: Compare two dictionaries for duplicate keys. if raise_error is True
      then raise on exception, otherwise log return True.