RGW: what is RGWCopyObj used for?

[Xinying Song <songxinying.ftd@xxxxxxxxx>]

Hi, cephers:
Can anybody give some explains about RGWCopyObj? It seems what
RGWCopyObj can do can also be done by RGWPutObj. And RGWPutObj does
more, it can handle copy-source-range header and uploadId. Why do we
still retain RGWCopyObj？

Thanks！