@Override
  public List<String> extractPartitionValuesInPath(String partitionPath) {
    // If the partitionPath is empty string( which means none-partition table), the partition values
    // should be empty list.
    if (partitionPath.isEmpty()) {
      return Collections.emptyList();
    }
    String[] splits = partitionPath.split("/");
    return Arrays.stream(splits).map(s -> {
      if (s.contains("=")) {
        String[] moreSplit = s.split("=");
        ValidationUtils.checkArgument(moreSplit.length == 2, "Partition Field (" + s + ") not in expected format");
        return moreSplit[1];
      }
      return s;
    }).collect(Collectors.toList());
  }
@Test
  public void testMultiPartExtractor() {
    MultiPartKeysValueExtractor valueExtractor = new MultiPartKeysValueExtractor();
    // Test extract empty partitionPath
    assertEquals(new ArrayList<>(), valueExtractor.extractPartitionValuesInPath(""));
    List<String> expected = new ArrayList<>();
    expected.add("2021-04-25");
    expected.add("04");
    // Test extract multi-partition path
    assertEquals(expected, valueExtractor.extractPartitionValuesInPath("2021-04-25/04"));
    // Test extract hive style partition path
    assertEquals(expected, valueExtractor.extractPartitionValuesInPath("ds=2021-04-25/hh=04"));
  }