private Xpp3Dom setUpSpringBootFatJar() {
    Xpp3Dom pluginConfiguration = new Xpp3Dom("configuration");
    PluginExecution execution = mock(PluginExecution.class);
    Plugin plugin = mock(Plugin.class);
    when(mockMavenProject.getPlugin("org.springframework.boot:spring-boot-maven-plugin"))
        .thenReturn(plugin);
    when(plugin.getExecutions()).thenReturn(Arrays.asList(execution));
    when(execution.getGoals()).thenReturn(Arrays.asList("repackage"));
    when(execution.getConfiguration()).thenReturn(pluginConfiguration);
    return pluginConfiguration;
  }
Helper for reading back layers in a {@link BuildContext}.
jib-maven-plugin/src/test/java/com/google/cloud/tools/jib/maven/MavenProjectPropertiesTest.java