@Override
    public void start() {
        PatternLayout patternLayout = new PatternLayout();
        patternLayout.setContext(context);
        patternLayout.setPattern(getPattern());
        patternLayout.setOutputPatternAsHeader(outputPatternAsHeader);
        patternLayout.start();
        this.layout = patternLayout;
        super.start();
    }
@Test
    public void isStarted() throws IOException {
        assertTrue(!ple.isStarted());
        ple.start();
        assertTrue(ple.isStarted());
    }