input: 
  def get_available_commands() -> List[str]:
      """Return a list of available commands for the Subtitles Client.
      >>> get_available_commands()
      ['download', 'exist', 'test', 'list', 'help', 'version']
      """
  
output:     return ['download', 'exist', 'test', 'list', 'help', 'version']