code: def validate_config_must_have(config, required_keys):
    
    missing_keys = set(required_keys) - set(config)
    if len(missing_keys) > 0:
      raise Exception('Invalid config with missing keys "%s"' % ', '.join(missing_keys))
docs: Validate a config dictionary to make sure it has all of the specified keys
  
    Args:
      config: the config to validate.
      required_keys: the list of possible keys that config must include.
  
    Raises:
      Exception if the config does not have any of them.