@Override
	public Object get(Address addr) {
		return null;
	}
Construct a dummy property map.
@param dbHandle database handle.
@param openMode the mode that the program was openned in or null if instantiated during
cache invalidate.  Used to detect versioning error only.
@param errHandler database error handler.
@param changeMgr change manager for event notification	 
@param addrMap address map.
@param name property name.
@param monitor progress monitor that is only used when upgrading
@throws VersionException if the database version is not the expected version.
@throws CancelledException if the user cancels the upgrade operation.
@throws IOException if a database io error occurs.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/properties/UnsupportedMapDB.java