@Test(expected = SamzaException.class)
  public void testRewriteConfigConfigRewritersEmptyString() {
    Config config = new MapConfig(ImmutableMap.of(JobConfig.CONFIG_REWRITERS, ""));
    ConfigUtil.rewriteConfig(config);
  }
This fails because Util will interpret the empty string value as a single rewriter which has the empty string as a
name, and there is no rewriter class config for a rewriter name which is the empty string.
TODO: should this be fixed to interpret the empty string as an empty list?
samza-core/src/test/java/org/apache/samza/util/TestConfigUtil.java