@Override
	public boolean isUpgraded() {
		return getOldAddressMap() != this;
	}
Returns an address map which may be used during the upgrade of old address
encodings.  If the address map is up-to-date, then this method will return
this instance of AddressMapDB.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/map/AddressMapDB.java