cesiumDemo/Source/Scene/TileDiscardPolicy.js

import DeveloperError from '../Core/DeveloperError.js';

    /**
     * A policy for discarding tile images according to some criteria.  This type describes an
     * interface and is not intended to be instantiated directly.
     *
     * @alias TileDiscardPolicy
     * @constructor
     *
     * @see DiscardMissingTileImagePolicy
     * @see NeverTileDiscardPolicy
     */
    function TileDiscardPolicy(options) {
        DeveloperError.throwInstantiationError();
    }

    /**
     * Determines if the discard policy is ready to process images.
     * @function
     *
     * @returns {Boolean} True if the discard policy is ready to process images; otherwise, false.
     */
    TileDiscardPolicy.prototype.isReady = DeveloperError.throwInstantiationError;

    /**
     * Given a tile image, decide whether to discard that image.
     * @function
     *
     * @param {Image} image An image to test.
     * @returns {Boolean} True if the image should be discarded; otherwise, false.
     */
    TileDiscardPolicy.prototype.shouldDiscardImage = DeveloperError.throwInstantiationError;
export default TileDiscardPolicy;