@Override
    public ConfigData get(String path) {
        return get(path, Files::isRegularFile);
    }
@Test
    public void testNonConfiguredProvider() {
        DirectoryConfigProvider provider2 = new DirectoryConfigProvider();
        IllegalStateException ise = assertThrows(IllegalStateException.class, () -> provider2.get(Paths.get(dir).toString()));
        assertEquals("The provider has not been configured yet.", ise.getMessage());
    }