@Test
public void should_migrate_style_asset_to_add_new_modal_container_css_classes() throws Exception {

    Asset style = anAsset().withType(CSS).withName("style.css").build();
    String initContent = ".my-content {background: red}";
    Page page = aPage()
            .withVersion("1.7.9").withAsset(style).build();
    when(pageAssetService.getAssetContent(page, style)).thenReturn(initContent);
    InputStream is = this.getClass().getClassLoader().getResourceAsStream("templates/migration/assets/css/styleAddModalContainerProperties.css");
    String content = initContent.concat(IOUtils.toString(is));
    step.migrate(page);
    verify(pageAssetService).save(page, expectedAsset("style.css"), content.getBytes());
}