static void findCommon(Map<String, String> commonValuesMap,
      Map<String, String> additionalValuesMap) {

    Set<String> sharedKeySet = commonValuesMap.keySet();
    sharedKeySet.retainAll(additionalValuesMap.keySet());

    for (String sharedKey : new HashSet<>(sharedKeySet)) {
      String commonNdValue = commonValuesMap.get(sharedKey);
      String incomingNdValue = additionalValuesMap.get(sharedKey);
      if (commonNdValue != null && !commonNdValue.equals(incomingNdValue)
          || commonNdValue == null && incomingNdValue != null) {
        commonValuesMap.remove(sharedKey);
      }
    }
  }
Removes any key-value pairs from @commonValuesMap that do not agree with the respective
key-value pairs of @additionalValuesMap

@param commonValuesMap Common values map, whose key set will be reduced.
@param additionalValuesMap Incoming values map, against which @commonValuesMap.
geode-gfsh/src/main/java/org/apache/geode/management/internal/cli/domain/RegionDescription.java