def METHOD_NAME(self):
    """
    Instanciating this plugin with an instance but no background image should render
    a default image in the html.
    The default image is defined as background image in the CSS.
    """
    placeholder = Placeholder.objects.create(slot="test")
    # Create random values for parameters with a factory
    large_banner = LargeBannerFactory(background_image=None)
    fields_list = [
        "title",
        "background_image",
        "logo",
        "logo_alt_text",
        "template",
        "content",
    ]
    model_instance = add_plugin(
        placeholder,
        LargeBannerPlugin,
        "en",
        **{field: getattr(large_banner, field) for field in fields_list},
    )
    # Get the generated html
    renderer = ContentRenderer(request=RequestFactory())
    html = renderer.render_plugin(model_instance, {})
    # Check that all expected elements are in the html
    self.assertIn('class="large-banner"', html)
    self.assertFalse('class="large-banner__background"' in html)
    self.assertIn('class="large-banner__content"', html)