@Test
    public void fileUtilsToBytesByFileNotExistsTest() {
        File file = new File("");
        Assertions.assertThrows(IOException.class, () -> HttpUtils.FileUtils.toBytes(file));
    }
HTTP request tool test {@link HttpUtils}.
shenyu-admin/src/test/java/org/apache/shenyu/admin/utils/HttpUtilsTest.java