@Override
    public SystemStreamPartitionGrouper getSystemStreamPartitionGrouper(Config config) {
      // check that the "processor.list" gets passed through the config
      assertEquals(ImmutableSet.of("0", "1"), ImmutableSet.copyOf(config.get(JobConfig.PROCESSOR_LIST).split(",")));
      return new Partition0Separate();
    }
Unfortunately, we still need powermock for testing the regex topic flow, since that flow checks for a specific
rewriter class, and setting up the support for that specific class is too cumbersome.
Many of the tests do not need powermock.
samza-core/src/test/java/org/apache/samza/coordinator/TestJobModelCalculator.java