+ downloader.add_option(
+ '--retry-sleep',
+ dest='retry_sleep', metavar='[TYPE:]EXPR', default={}, type='str',
+ action='callback', callback=_dict_from_options_callback,
+ callback_kwargs={
+ 'allowed_keys': 'http|fragment|file_access',
+ 'default_key': 'http',
+ }, help=(
+ 'An expression for the time to sleep between retries in seconds (optionally) prefixed '
+ 'by the type of retry (file_access, fragment, http (default)) to apply the sleep to. '
+ 'EXPR can be a number, linear=START[:END[:STEP=1]] or exp=START[:END[:BASE=2]]. '
+ 'This option can be used multiple times to set the sleep for the different retry types. '
+ 'Eg: --retry-sleep linear=1::2 --retry-sleep fragment:exp=1:20'))