private void assertInCollection(String message, Collection<? extends PartitionId> expected, PartitionId actual) {
    if (expected != null) {
      assertTrue(message, expected.contains(actual));
    } else {
      assertEquals(message, null, expected);
    }
  }
Asserts that element {@code actual} is equal to the one of the elements in {@code expected} collection.
@param message the message to print if not found.
@param expected the expected elements
@param actual the actual element
ambry-clustermap/src/test/java/com/github/ambry/clustermap/ClusterMapUtilsTest.java