@Test
  public void testExecute_simple_extraDirectoriesFiltering()
      throws DigestException, IOException, InterruptedException, VerificationException {
    String targetImage = "simpleimage:maven" + System.nanoTime();
    buildToDockerDaemon(simpleTestProject, targetImage, "pom-extra-dirs-filtering.xml");
    String output =
        new Command("docker", "run", "--rm", "--entrypoint=ls", targetImage, "-1R", "/extras")
            .run();

    //   /extras/cat.txt
    //   /extras/foo
    //   /extras/sub/
    //   /extras/sub/a.json
    assertThat(output).isEqualTo("/extras:\ncat.txt\nfoo\nsub\n\n/extras/sub:\na.json\n");
  }
Builds and runs jib:buildDocker on a project at {@code projectRoot} pushing to {@code
imageReference}.
jib-maven-plugin/src/integration-test/java/com/google/cloud/tools/jib/maven/BuildDockerMojoIntegrationTest.java