@Override
    public boolean isReadable(Class serializableClass, Type type, Annotation[] annotations, MediaType mediaType) {
        return isSupportedMediaType(mediaType) && isSupportedCharset(mediaType) && isSupportedEntity(serializableClass);
    }
@Test
    public void testNonUtf8CharsetIsNotAccepted() throws Exception {
        Map<String, String> params = new HashMap<>();
        params.put("charset", "ISO-8859");
        MediaType mediaTypeWithNonSupportedCharset = new MediaType("application", "json", params);

        assertThat(jerseyProvider.isReadable(InstanceInfo.class, InstanceInfo.class, null, mediaTypeWithNonSupportedCharset), is(false));
    }