Merge pull request #7078 from geosense/vectortile_layer_getsource_return_type

Fix return type annotation of ol.layer.VectorTile.getSource

src/ol/layer/vectortile.js

@@ -116,3 +116,12 @@ ol.layer.VectorTile.prototype.setUseInterimTilesOnError = function(useInterimTil
   this.set(
       ol.layer.TileProperty.USE_INTERIM_TILES_ON_ERROR, useInterimTilesOnError);
 };
+
+
+/**
+ * Return the associated {@link ol.source.VectorTile vectortilesource} of the layer.
+ * @function
+ * @return {ol.source.VectorTile} Source.
+ * @api
+ */
+ol.layer.VectorTile.prototype.getSource;