assertTrue("No such resource: " + op + "\n\nActual:\n" + actual, is != null);
if (is == null) { return "No such resource: " + op + "\n\nTest output:\n" + actual; }
    private String compare(String expectedResource, String actual) {        String op = "com/arsdigita/persistence/oql/" + expectedResource;        InputStream is = getClass().getClassLoader().getResourceAsStream(op);        assertTrue("No such resource: " + op + "\n\nActual:\n" + actual,                   is != null);        Reader reader = new InputStreamReader(is);        StringBuffer expected = new StringBuffer();        char[] buf = new char[1024];        try {            while (true) {                int n = reader.read(buf);                if (n < 0) { break; }                expected.append(buf, 0, n);            }        } catch (IOException e) {            fail(e.getMessage());        }        String result = diff(expected.toString(), actual);        if (result != null) {            result = expectedResource + ": " + result;        }        return result;    }