@Override
    public AbstractHttpMessageBuilder content(MediaType contentType, byte[] content) {
        requireNonNull(content, "content");
        return content(contentType, HttpData.wrap(content));
    }
Returns the {@link Publisher} that was set by {@link #content(MediaType, Publisher)}.
core/src/main/java/com/linecorp/armeria/common/AbstractHttpMessageBuilder.java