def METHOD_NAME(config, force_update=True):
    """Add the space definition at the root of config."""
    if "space" in config and not force_update:
        return
    populate_priors(config["metadata"])
    # Overwrite space to make sure to include changes from user_args
    if "priors" in config["metadata"]:
        log.debug("Updating space for backward compatibility")
        log.debug(pprint.pformat(config["metadata"]["priors"]))
        config["space"] = config["metadata"]["priors"]