def drop_flag_values(self):
    """Returns a copy of these options that ignores values specified via flags.

    Any pre-cached option values are cleared and only option values that come from option defaults,
    the config or the environment are used.
    """
    # An empty scope_to_flags to force all values to come via the config -> env hierarchy alone
    # and empty values in case we already cached some from flags.
    no_flags = {}
    return Options(self._goals,
                   no_flags,
                   self._target_specs,
                   self._passthru,
                   self._passthru_owner,
                   self._help_request,
                   self._parser_hierarchy,
                   self._bootstrap_option_values,
                   self._known_scope_to_info,
                   self._option_tracker,
                   self._unknown_scopes)
Returns a copy of these options that ignores values specified via flags.

    Any pre-cached option values are cleared and only option values that come from option defaults,
    the config or the environment are used.