@Test
  public void testImageLayout() throws IOException {
    Set<String> paths = new HashSet<>();
    layerEntriesDo(
        (layerName, layerEntry) -> {
          if (layerEntry.isFile()) {
            paths.add(layerEntry.getName());
          }
        });
    assertThat(paths)
        .containsExactly(
            "app/fileA.txt",
            "app/fileB.txt",
            "app/fileC.txt",
            "app/fileD.txt",
            "app/subdir/fileE.txt");
  }
Verify that created image has explicit directory structures, default timestamps, permissions, and
file orderings.
jib-core/src/integration-test/java/com/google/cloud/tools/jib/api/ReproducibleImageTest.java