@PublicAPI(usage = ACCESS)
    public Optional<String> getFileName() {
        return fileName;
    }
@Test
    public void source_file_name() {
        Source source = new Source(uriOf(Object.class), Optional.of("SomeClass.java"), false);
        assertThat(source.getFileName()).as("source file name").contains("SomeClass.java");

        source = new Source(uriOf(Object.class), Optional.empty(), false);
        assertThat(source.getFileName()).as("source file name").isEmpty();
    }