@Override
  public byte[] serialize(final String topic, final List<?> values) {
    if (values == null) {
      return null;
    }

    final T single = extractOnlyColumn(values, topic);
    return inner.serialize(topic, single);
  }
@Test
  public void shouldThrowIfWrongType() {
    // Then:
    final Exception e = assertThrows(
        SerializationException.class,
        () -> serializer.serialize("t", ImmutableList.of(12))
    );

    // Then:
    assertThat(e.getMessage(), is("value does not match expected type. "
        + "expected: String, but got: Integer"));
  }