String etag = header.getHeader ("Etag");
if (etag != null && !con.isWeak (etag))
copyHeaderIfExists ("Expires", oldresp, header);
List<String> ccs = oldresp.getHeaders ("Cache-Control");
for (int i = 0, s = ccs.size (); i < s; i++)
header.addHeader ("Cache-Control", ccs.get (i));
ccs = oldresp.getHeaders ("Vary");
for (int i = 0, s = ccs.size (); i < s; i++)
header.addHeader ("Vary", (String)ccs.get (i));
return header;
}