public static InputStream getResourceAsStream(String resource) throws IOException {
        ClassLoader loader = ResourceUtils.class.getClassLoader();
        return getResourceAsStream(loader, resource);
    }
@Test
    void testGetResourceAsStreamForClasspathFromSystem() throws IOException {
        try (InputStream inputStream = ResourceUtils.getResourceAsStream(null, "test-tls-cert.pem")) {
            assertNotNull(inputStream);
        }
    }