docs: def _get_format(value, quote_mode='always'):
      """
      Returns the quote format depending on the quote_mode.
      This determines if the key value will be quoted when written to
      the env file.
  
      :param value:
      :param quote_mode:
      :return: str
      :raises: KeyError if the quote_mode is unknown
      """
  
      formats = {'always': '{key}="{value}"\n', 'auto': '{key}={value}\n'}
  
      if quote_mode not in formats.keys():
          return KeyError(f'quote_mode {quote_mode} is invalid')
  
      _mode = quote_mode
      if quote_mode == 'auto' and ' ' in value:
          _mode = 'always'
      return formats.get(_mode)