private void handleConsumesAnnotation(Consumes consumes, MethodMetadata data) {
    final String[] serverConsumes =
        removeValues(consumes.value(), mediaType -> emptyToNull(mediaType) == null, String.class);
    checkState(serverConsumes.length > 0, "Consumes.value() was empty on %s", data.configKey());
    data.template().header(CONTENT_TYPE, serverConsumes);
  }
Please refer to the <a href="https://github.com/Netflix/feign/tree/master/feign-jaxrs">Feign
JAX-RS README</a>.
jaxrs/src/main/java/feign/jaxrs/JAXRSContract.java