question: private String readNodeAddress ( ) { String addr = "" ; addr = ( String ) nodeAddrField . getSelectedItem ( ) ; if ( addr == null || addr . equals ( "FF FE " ) || addr . equals ( "FF FF " ) ) { addr = ( String ) nodeAddr64Field . getSelectedItem ( ) ; if ( addr == null ) throw new IllegalArgumentException ( "Invalid Address" ) ; } return ( addr ) ; }
target:  Read selected node address.