Function enableClassExtend

libs/echarts/echarts-en.simple.js:12244–12280

* @public

(RootClass, mandatoryMethods)

 * @public
 */
function enableClassExtend(RootClass, mandatoryMethods) {

    RootClass.$constructor = RootClass;
    RootClass.extend = function (proto) {

        if (__DEV__) {
            each$1(mandatoryMethods, function (method) {
                if (!proto[method]) {
                    console.warn(
                        'Method `' + method + '` should be implemented'
                        + (proto.type ? ' in ' + proto.type : '') + '.'
                    );
                }
            });
        }

        var superClass = this;
        var ExtendedClass = function () {
            if (!proto.$constructor) {
                superClass.apply(this, arguments);
            }
            else {
                proto.$constructor.apply(this, arguments);
            }
        };

        extend(ExtendedClass.prototype, proto);

        ExtendedClass.extend = this.extend;
        ExtendedClass.superCall = superCall;
        ExtendedClass.superApply = superApply;
        inherits(ExtendedClass, this);
        ExtendedClass.superClass = superClass;

        return ExtendedClass;
    };
}

var classBase = 0;