public static <T> Stream<T> ofNullable(Iterable<T> iterable) {
        return null == iterable ? Stream.empty() : stream(iterable);
    }
public static < T > Stream < T > ofNullable ( Iterable < T > iterable ) { return null == iterable ? Stream . empty ( ) : stream ( iterable ) ; }
Converts a nullable Iterable into a Stream.
@param iterable The iterable to stream.
@param <T> The type of the iterable
@return Stream of the values returned by the iterable, or an empty stream if the iterable is null