def _gather(self, func):
        """
        Removes the experiment's path (prefix) from the names of the gathered
        items. This means that, for example, 'experiment.print_config' becomes
        'print_config'.
        """
        for ingredient, _ in self.traverse_ingredients():
            for name, item in func(ingredient):
                if ingredient == self:
                    name = name[len(self.path) + 1:]
                yield name, item