In `org.eclipse.jetty.proxy.Transparent`, I see the following check in the `rewriteURI` method:

```java
            String path = request.getRequestURI();
            if (!path.startsWith(_prefix))
                return null;
```

where `_prefix` includes the context path under which the servlet was installed.  This makes me wonder if it is possible for Jetty to call into this servlet for requests that don't match the context path under which the servlet handler was registered.  Do we know if this can be the case and, if so, should we then have a similar clause to return null if it were called in this manner?