docs: public Integer getBlockMaskPrefixLength(boolean network) {
  		Integer prefixLen;
  		if(network) {
  			if(hasNoPrefixCache() || (prefixLen = prefixCache.networkMaskPrefixLen) == null) {
  				prefixLen = setNetworkMaskPrefix(checkForPrefixMask(network));
  			}
  		} else {
  			if(hasNoPrefixCache() || (prefixLen = prefixCache.hostMaskPrefixLen) == null) {
  				prefixLen = setHostMaskPrefix(checkForPrefixMask(network));
  			}
  		}
  		if(prefixLen < 0) {
  			return null;
  		}
  		return prefixLen;
  	}