private Configuration createSomeRealConfiguration(
     final Random valueGenerator, final Set<String>... keySets) {
   final ConfigBuilder builder = ConfigBuilder.buildConfig(ConfigSource.EMPTY_SOURCE);
   if (keySets.length == 1) {
     for (final String key : keySets[0]) {
       builder.select(key).addValue(valueGenerator.nextFloat()).back();
     }
   } else if (keySets.length > 1) {
     for (final String key : keySets[0]) {
       final Configuration tmpCfg =
           createSomeRealConfiguration(
               valueGenerator, Arrays.copyOfRange(keySets, 1, keySets.length));
       builder.select(key).addConfig(tmpCfg).back();
     }
   }
   return builder.getConfig();
 }