public Set<String> getKeys(boolean deep) {
        Set<String> result = new LinkedHashSet<String>();

        Configuration root = getRoot();
        if (root != null && root.options().copyDefaults()) {
            ConfigurationSection defaults = getDefaultSection();

            if (defaults != null) {
                result.addAll(defaults.getKeys(deep));
            }
        }

        mapChildrenKeys(result, this, deep);

        return result;
    }