src/browser/polyfill.js
/**
         * Test is MutationObserver is supported
         *
         * @returns {boolean}
         */
Test is MutationObserver is supported
@returns {boolean}
Test is MutationObserver is supported @returns { boolean }
function testObserver() {
            if (!global.MutationObserver || !global.WeakMap) {
                if (!queued.observer) {
                    queued.observer = load(config._webComponentsPolyfill);
                }
            }
            return true;
        }
function testObserver ( ) { if ( ! global . MutationObserver || ! global . WeakMap ) { if ( ! queued . observer ) { queued . observer = load ( config . _webComponentsPolyfill ) ; } } return true ; }
Test is MutationObserver is supported
 @returns {boolean}
Test is MutationObserver is supported @returns { boolean }