code: @Override
  	public String toCompressedString() {
  		String result;
  		if(hasNoStringCache() || (result = stringCache.compressedString) == null) {
  			if(hasZone()) {
  				stringCache.compressedString = result = toNormalizedString(IPv6StringCache.compressedParams);
  			} else {
  				result = getSection().toCompressedString();//the cache is shared so no need to update it here
  			}
  		}
  		return result;
  	}
docs: This compresses the maximum number of zeros and/or host segments with the IPv6 compression notation '::'