docs: @Override
      public final <RQ, RS> Maybe<Response<RS>> post(String resource, RQ rq, Type type)
              throws RestEndpointIOException {
          HttpPost post = new HttpPost(spliceUrl(resource));
          Serializer serializer = getSupportedSerializer(rq);
          ByteArrayEntity httpEntity = new ByteArrayEntity(serializer.serialize(rq),
                  ContentType.create(serializer.getMimeType()));
          post.setEntity(httpEntity);
          return executeInternal(post, new TypeConverterCallback<RS>(serializers, type));
      }