[wicket 6] How to get InputStream from ResourceReference ?

[smallufo]

In wicket 1.4
I can get InputStream from a ResourceReference :

ResourceReference resRef = new ResourceReference(Page.class , "xxx.png");
InputStream is = resRef.getResource().getResourceStream().getInputStream();

But it seems invalid in wicket 6

I need to build a DynamicImageResource , which returns byte[] in
getImageData()
ResourceReference resRef = new PackageResourceReference(Page.class ,
"xxx.png");
(in fact , the true resRef depends on the attributes parameter)

but I am stuck here.
I find no way to get InputStream of resRef , so I cannot transform
InputStream to byte[].

Any solutions ?

Thanks !