ddt_object_lookup
ASSERT(ddt_object_lookup(ddt, otype, oclass, dde) == ENOENT);
error = ddt_object_lookup(ddt, type, class, dde);
if (ddt_object_lookup(ddt, type, class, &dde) == 0)
ddt_object_lookup(ddt, type, class, dde) == 0)