code: @Override
  	public String toCanonicalString() {
  		String result;
  		if(hasNoStringCache() || (result = getStringCache().canonicalString) == null) {
  			getStringCache().canonicalString = result = toNormalizedString(MACStringCache.canonicalParams);
  		}
  		return result;
  	}
docs: This produces a canonical string using the canonical standardized IEEE 802 MAC address representation of xx-xx-xx-xx-xx-xx
  For range segments, '..' is used: 11-22-33..44-55-66