@CheckReturnValue
    default SplitHttpResponse split() {
        return split(defaultSubscriberExecutor());
    }
Returns a new {@link SplitHttpResponse} which splits a stream of {@link HttpObject}s into
{@link HttpHeaders} and {@link HttpData}.
{@link SplitHttpResponse#headers()} will be
completed before publishing the first {@link HttpData}.
{@link SplitHttpResponse#trailers()} might not complete until the entire response body is consumed
completely.
core/src/main/java/com/linecorp/armeria/common/HttpResponse.java