@Override
    @Deprecated
    public <K1, V1> KStream<K1, V1> flatTransform(final org.apache.kafka.streams.kstream.TransformerSupplier<? super K, ? super V, Iterable<KeyValue<K1, V1>>> transformerSupplier,
                                                  final String... stateStoreNames) {
        Objects.requireNonNull(transformerSupplier, "transformerSupplier can't be null");
        final String name = builder.newProcessorName(TRANSFORM_NAME);
        return flatTransform(transformerSupplier, Named.as(name), stateStoreNames);
    }
@Test
    @SuppressWarnings("deprecation")
    public void shouldNotAllowNullStoreNamesOnFlatTransformWithNamed() {
        final NullPointerException exception = assertThrows(
            NullPointerException.class,
            () -> testStream.flatTransform(flatTransformerSupplier, Named.as("flatTransform"), (String[]) null));
        assertThat(exception.getMessage(), equalTo("stateStoreNames can't be a null array"));
    }