assertNotNull(path_in+": file not found.", is_in);
assertNotNull(path_out+": file not found.", is_out);
Configuration cfg = ConfigurationFactory.newInstance().parseInputStream(is_in);
ByteArrayOutputStream ba = new ByteArrayOutputStream();
new ConfigurationWriter(cfg).writeTo(new OutputStreamWriter(ba));
byte[] config_real = ba.toByteArray();
byte[] config_expected = IOUtils.toByteArray(is_out);
String string_real = new String(config_real);