@Test
    @Timeout(300)
    void testContentHeader() {
        assertEquals("utf-8", renderer.getEncoding());
        assertEquals("application/json", renderer.getMimeType());
    }
Functional testing of {@link JsonRenderer}.

@author Steinar Knutsen
@author bratseth
container-search/src/test/java/com/yahoo/search/rendering/JsonRendererTestCase.java