protected Dependency scanFile(@NotNull final File file) {
        return scanFile(file, null);
    }
@Test
    public void testScanFile() throws DatabaseException {
        try (Engine instance = new Engine(getSettings())) {
            instance.addFileTypeAnalyzer(new JarAnalyzer());
            File file = BaseTest.getResourceAsFile(this, "dwr.jar");
            Dependency dwr = instance.scanFile(file);
            file = BaseTest.getResourceAsFile(this, "org.mortbay.jmx.jar");
            instance.scanFile(file);
            assertEquals(2, instance.getDependencies().length);

            file = BaseTest.getResourceAsFile(this, "dwr.jar");
            Dependency secondDwr = instance.scanFile(file);

            assertEquals(2, instance.getDependencies().length);
        }
    }