@VisibleForTesting
    static Optional<String> findEntryClass(File jarFile) throws IOException {
        return findFirstManifestAttribute(
                jarFile,
                PackagedProgram.MANIFEST_ATTRIBUTE_ASSEMBLER_CLASS,
                PackagedProgram.MANIFEST_ATTRIBUTE_MAIN_CLASS);
    }
@Test
    void testFindEntryClassWithTestJobJar() throws IOException {
        File jarFile = TestJob.getTestJobJar();

        Optional<String> entryClass = JarManifestParser.findEntryClass(jarFile);

        assertThat(entryClass).get().isEqualTo(TestJob.class.getCanonicalName());
    }