inheritsFromStyle function
Whether prop of node is what its style says — set by the style and
equal to it. "Equal means inherited": there is no override flag, by
decision, so a property overridden back to the style's own value is
inherited again and follows the style.
Implementation
bool inheritsFromStyle(SceneDocument doc, SceneNode node, String prop) {
var style = styleOf(doc, node);
if (style == null || !style.sets(prop)) return false;
return sceneValuesEqual(getSceneProperty(node, prop), style.values[prop]);
}