@SuppressWarnings("unchecked") public static <K>ImmutableArray2<K> empty(){
  return (ImmutableArray2<K>)EMPTY;
}

@ SuppressWarnings ( "unchecked" ) public static < K > ImmutableArray2 < K > empty ( ) { return ( ImmutableArray2 < K > ) EMPTY ; }
get an empty immutable array .
