function getSetPrefixed(propertyName, unprefixed) {
    return function (element, propertyValue) {
        if (propertyValue === undefined) {
            return computePropertyValue(element, propertyName) || computePropertyValue(element, unprefixed);
        }
        element.style[propertyName] = element.style[unprefixed] = propertyValue;
    };
}
Return a Normalisation that can be used to set / get a prefixed style
property.