Better docs for ol.layer.Vector#setStyle

src/ol/layer/vectorlayer.js

@@ -101,7 +101,10 @@ ol.layer.Vector.prototype.setRenderOrder = function(renderOrder) {
 /**
  * Set the style for features.  This can be a single style object, an array
  * of styles, or a function that takes a feature and resolution and returns
- * an array of styles. If `undefined` default styles are used.
+ * an array of styles. If it is `undefined` the default style is used. If
+ * it is `null` the layer has no style (a `null` style), so only features
+ * that have their own styles will be rendered in the layer. See
+ * {@link ol.style} for information on the default style.
  * @param {ol.style.Style|Array.<ol.style.Style>|ol.style.StyleFunction|undefined}
  *     style Layer style.
  * @api stable