code: @Test public void disableSerializationFeature() throws Exception {
    this.context.register(JacksonAutoConfiguration.class);
    EnvironmentTestUtils.addEnvironment(this.context,"spring.jackson.serialization.write_dates_as_timestamps:false");
    this.context.refresh();
    ObjectMapper mapper=this.context.getBean(ObjectMapper.class);
    assertTrue(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS.enabledByDefault());
    assertFalse(mapper.getSerializationConfig().hasSerializationFeatures(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS.getMask()));
  }
  