code: public static NetworkAddress parse(String networkAddress) {
  		NetworkAddress address = null;
  		if (networkAddress != null) {
  			String[] split = networkAddress.split("/");
  			if (split.length == 2) {
  				byte[] network = parseDottedQuad(split[0]);
  				byte[] netmask = parseDottedQuad(split[1]);
  				address = toNetworkAddress(network, netmask);
  			}
  			else {
  				throw new IllegalArgumentException("Network address must be ip4Address/netMask");
  			}
  		}
  		return address;
  	}
docs: parse a network address identifier, consisting of an ip4Address/netMask, where both ip4Address and netMask are
  presented in dotted quad notation.  e.g. 92.6.4.0/255.255.255.0
  @return