 elementName
    );
    let instance = document.createElement(elementName, { is: element.name });
    // source element as a child of a picture element, before the img element
    parentElement.prepend(instance);

    assert_array_equals(element.takeLog().types(), ['constructed', 'connected']);
    instance[jsAttributeName] = validValue1;
    assert_array_equals(element.takeLog().types(), ['attributeChanged']);
    instance[jsAttributeName] = validValue2;
    let logEntries = element.takeLog();
    assert_a