code: public final synchronized void setDomainAddress(final byte[] domain)
  	{
  		if (domain == null)
  			doa = broadcastDomain;
  		else if (domain.length != 6)
  			throw new KNXIllegalArgumentException("invalid length of domain address");
  		else
  			doa = (byte[]) domain.clone();
  	}
docs: Sets a new domain address.
  <p>
  
  @param domain byte array containing the domain address to use in KNX messages,
  address is given in network byte order, <code>domain.length</code> = 6,
  supplying <code>null</code> defaults to the broadcast domain