private BufferedYamlConfiguration loadConfig(final File base, final String world) {
        BufferedYamlConfiguration config = this.configuration.get(world);
        if (config != null) return config;

        final File source = (world == null ? base : new File(base, world + ".yml"));
        try {
            config = new BufferedYamlConfiguration(this.plugin, source, this.minSave).load();
        } catch (final FileNotFoundException e) {
        } catch (final Exception e) {
            throw new IllegalStateException("Unable to load region configuration file: " + source, e);
        }

        this.configuration.put(world, config);
        return config;
    }