XMLBuilder grantBuilder = grantsBuilder.elem("Grant");
XMLBuilder granteeBuilder = grantBuilder.elem("Grantee").attr("xmlns:xsi",
"http://www.w3.org/2001/XMLSchema-instance");
if (grant.getGrantee() instanceof GroupGrantee) {
granteeBuilder.attr("xsi:type", "Group").elem("URI").text(grant.getGrantee().getIdentifier());
} else if (grant.getGrantee() instanceof CanonicalUserGrantee) {
CanonicalUserGrantee grantee = (CanonicalUserGrantee) grant.getGrantee();
granteeBuilder.attr("xsi:type", "CanonicalUser").elem("ID").text(grantee.getIdentifier()).up();
if (grantee.getDisplayName() != null) {
granteeBuilder.elem("DisplayName").text(grantee.getDisplayName());