@Test
public void testFormatBackTrace() {

    Exception e = new IOException("Fake I/O");
    e = new Exception(e.toString(), e);
    assertNotNull(e.getMessage(), e.getMessage());
    CompactFormatter cf = new CompactFormatter();
    LogRecord record = new LogRecord(Level.SEVERE, "");
    record.setThrown(e);
    String result = cf.formatBackTrace(record);
    assertTrue(result, result.startsWith("CompactFormatterTest"));
    assertTrue(result, result.contains("testFormatBackTrace"));
    assertTrue(result, Character.isDigit(result.charAt(result.length() - 2)));
}