public synchronized OutputStream open() {
        try {
            close();
            fileOutputStream = new FileOutputStream(file, true);
        } catch (FileNotFoundException e) {
            throw new RuntimeException("Unable to open output stream", e);
        }
        return fileOutputStream;
    }
@Test
    public void requireThatFileCanOpened() throws IOException {
        FileLogTarget logTarget = new FileLogTarget(File.createTempFile("logfile", ".log"));
        assertNotNull(logTarget.open());
    }