@Test public void extract_prefixed() {

  factory = newFactoryBuilder(B3Propagation.FACTORY)
    .addField("x-vcap-request-id")
    .addPrefixedFields("baggage-", asList("country-code"))
    .build();
  initialize();
  injector.inject(context, request);
  request.put("baggage-country-code", "FO");
  request.put("x-vcap-request-id", uuid);
  TraceContextOrSamplingFlags extracted = extractor.extract(request);
  assertThat(extracted.context().toBuilder().extra(Collections.emptyList()).build())
    .isEqualTo(context);
  assertThat(extracted.context().extra())
    .hasSize(2);
  assertThat(BaggageField.getByName(extracted, "country-code").getValue(extracted))
    .isEqualTo("FO");
  assertThat(BaggageField.getByName(extracted, "x-vcap-request-id").getValue(extracted))
    .isEqualTo(uuid);
}