private Map<String, String> removeProperties(Map<String, String> originalProperties,
                                               Set<String> removeList, Multimap<AbstractUpgradeCatalog.ConfigUpdateType, Entry<String, String>> propertiesToLog){
    Map<String, String> properties = new HashMap<>();
    properties.putAll(originalProperties);
    for (String removeProperty: removeList){
      if (originalProperties.containsKey(removeProperty)){
        properties.remove(removeProperty);
        propertiesToLog.put(ConfigUpdateType.REMOVED, new AbstractMap.SimpleEntry<>(removeProperty, ""));
      }
    }
    return properties;
  }
Create a new cluster scoped configuration with the new properties added
to the existing set of properties.
@param configType Configuration type. (hdfs-site, etc.)
@param properties Map of key value pairs to add / update.
ambari-server/src/main/java/org/apache/ambari/server/upgrade/AbstractUpgradeCatalog.java