private void assertExists(String key, String tableId, Map<String, String> config) {
    String realKey = JavaTableConfig.buildKey(tableId, key);
    Assert.assertTrue(config.containsKey(realKey));
  }
Testing caching in a more realistic scenario with Guava cache + remote table
samza-core/src/test/java/org/apache/samza/table/caching/TestCachingTable.java