docs: def unset_key(dotenv_path, key_to_unset, quote_mode='always', verbose=False):
      """
      Removes a given key from the given .env
  
      If the .env path given doesn't exist, fails
      If the given key doesn't exist in the .env, fails
  
      :param dotenv_path: env path
      :param key_to_unset: value
      :param quote_mode: quote value in .env file
      :param verbose: verbosity flag, raise warning if path does not exist
      :return: tuple (fail/win, key)
      """
      key_to_unset = str(key_to_unset)
      if not os.path.exists(dotenv_path):
          if verbose:
              warnings.warn(f"Can't delete from {dotenv_path}, it doesn't exist.")
          return None, key_to_unset
      dotenv_as_dict = dotenv_values(dotenv_path)
      if key_to_unset in dotenv_as_dict:
          dotenv_as_dict.pop(key_to_unset, None)
      else:
          if verbose:
              warnings.warn(f"Key {key_to_unset} not removed from {dotenv_path}, key doesn't exist.")
          return None, key_to_unset
  
      success = flatten_and_write(dotenv_path, dotenv_as_dict, quote_mode)
      return success, key_to_unset