Add @api annotations to ol.layer.Tile

src/ol/layer/tilelayer.js

@@ -37,6 +37,7 @@ goog.inherits(ol.layer.Tile, ol.layer.Layer);
 /**
  * @return {number|undefined} The level to preload tiles up to.
  * @observable
+ * @api
  */
 ol.layer.Tile.prototype.getPreload = function() {
   return /** @type {number|undefined} */ (
@@ -51,6 +52,7 @@ goog.exportProperty(
 /**
  * @param {number} preload The level to preload tiles up to.
  * @observable
+ * @api
  */
 ol.layer.Tile.prototype.setPreload = function(preload) {
   this.set(ol.layer.TileProperty.PRELOAD, preload);
@@ -63,6 +65,8 @@ goog.exportProperty(
 
 /**
  * @return {boolean|undefined} Use interim tiles on error.
+ * @observable
+ * @api
  */
 ol.layer.Tile.prototype.getUseInterimTilesOnError = function() {
   return /** @type {boolean|undefined} */ (
@@ -76,6 +80,8 @@ goog.exportProperty(
 
 /**
  * @param {boolean|undefined} useInterimTilesOnError Use interim tiles on error.
+ * @observable
+ * @api
  */
 ol.layer.Tile.prototype.setUseInterimTilesOnError =
     function(useInterimTilesOnError) {