@Override
  public Object clone() throws CloneNotSupportedException {
    AuthToLocalBuilder copy = (AuthToLocalBuilder) super.clone();

    /* **** Copy mutable members **** */
    copy.setRules = new TreeSet<>(setRules);

    return copy;
  }
Constructs a new AuthToLocalBuilder.

@param defaultRealm               a String declaring the default realm
@param additionalRealms           a collection of Strings declaring the set of realm names to
                                  incorporate into the generated rule set
@param caseInsensitiveUserSupport true indicating that case-insensitivity should be enabled;
                                  false otherwise
ambari-server/src/main/java/org/apache/ambari/server/controller/AuthToLocalBuilder.java