### Question:
JacksonJsonLayout extends AbstractLayout<ItemSource> implements ItemSourceLayout, LifeCycle { @Override public String getContentType() { return "application/json"; } protected  JacksonJsonLayout(Configuration config, ObjectWriter configuredWriter, ItemSourceFactory itemSourceFactory); @Override String getContentType(); @Override byte[] toByteArray(LogEvent event); @Override final ItemSource toSerializable(LogEvent event); @Override final ItemSource serialize(LogEvent event); @Override final ItemSource serialize(Message message); @PluginBuilderFactory static JacksonJsonLayout.Builder newBuilder(); @Override void start(); @Override void stop(); @Override boolean isStarted(); @Override boolean isStopped(); static final String PLUGIN_NAME; }### Answer:
@Test public void contentTypeIsNotNull() { JacksonJsonLayout layout = createDefaultTestBuilder().build(); String contentType = layout.getContentType(); assertNotNull(contentType); }