code: private Object cloneUnfrozenDII() //throws IllegalStateException
      {
          try {
              DateIntervalInfo other = (DateIntervalInfo) super.clone();
              other.fFallbackIntervalPattern=fFallbackIntervalPattern;
              other.fFirstDateInPtnIsLaterDate = fFirstDateInPtnIsLaterDate;
              if (fIntervalPatternsReadOnly) {
                  other.fIntervalPatterns = fIntervalPatterns;
                  other.fIntervalPatternsReadOnly = true;
              } else {
                  other.fIntervalPatterns = cloneIntervalPatterns(fIntervalPatterns);
                  other.fIntervalPatternsReadOnly = false;
              }
              other.frozen = false;
              return other;
          } catch ( CloneNotSupportedException e ) {
              ///CLOVER:OFF
              throw new  ICUCloneNotSupportedException("clone is not supported", e);
              ///CLOVER:ON
          }
      }
docs: /*
  Clone an unfrozen DateIntervalInfo object.
  @return     a copy of the object