public synchronized void add(IPv4Address address, IPv4Address subnetMask) { final IPv4AddressAndMask aam = new IPv4AddressAndMask(address, subnetMask);
public synchronized IPv4IfAddress add(IPv4Address address, IPv4Address mask) {
	public synchronized void add(IPv4Address address, IPv4Address subnetMask) {		final IPv4AddressAndMask aam = new IPv4AddressAndMask(address, subnetMask);		addresses.remove(address);		addresses.put(address, aam);	}