Adds `directories` to be blacklisted. Blacklisted directories will not
        be returned or searched recursively when calling the
        `collect_directories` method.

        `directories` may be a single instance or an iterable. Recommend
        passing in absolute paths, but method will try to convert to absolute
        paths based on the current working directory.

        If `remove_from_stored_directories` is true, all `directories`
        will be removed from `self.plugin_directories`

def add_blacklisted_directories(self,
                                    directories,
                                    remove_from_stored_directories=True):

        """
        Adds `directories` to be blacklisted. Blacklisted directories will not
        be returned or searched recursively when calling the
        `collect_directories` method.

        `directories` may be a single instance or an iterable. Recommend
        passing in absolute paths, but method will try to convert to absolute
        paths based on the current working directory.

        If `remove_from_stored_directories` is true, all `directories`
        will be removed from `self.plugin_directories`
        """
        absolute_paths = util.to_absolute_paths(directories)
        self.blacklisted_directories.update(absolute_paths)
        if remove_from_stored_directories:
            plug_dirs = self.plugin_directories
            plug_dirs = util.remove_from_set(plug_dirs,
                                             directories)