@Test
  public void testPermissions() throws IOException {
    assertThat(FilePermissions.DEFAULT_FILE_PERMISSIONS.getPermissionBits()).isEqualTo(0644);
    assertThat(FilePermissions.DEFAULT_FOLDER_PERMISSIONS.getPermissionBits()).isEqualTo(0755);
    layerEntriesDo(
        (layerName, layerEntry) -> {
          if (layerEntry.isFile()) {
            assertThat(layerEntry.getMode() & 0777).isEqualTo(0644);
          } else if (layerEntry.isDirectory()) {
            assertThat(layerEntry.getMode() & 0777).isEqualTo(0755);
          }
        });
  }
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