nl_tokens: Web component polyfills loader based on : https : // github . com / webcomponents / webcomponentsjs / blob / master / webcomponents - loader . js
pl_tokens: function needsTemplatePolyfill ( ) { // no real <template> because no `content` property (IE and older browsers) const template = document . createElement ( 'template' ) ; if ( ! ( 'content' in template ) ) { return true ; } // broken doc fragment (older Edge) if ( ! ( template . content . cloneNode ( ) instanceof DocumentFragment ) ) { return true ; } // broken <template> cloning (Edge up to at least version 17) const template2 = document . createElement ( 'template' ) ; template2 . content . appendChild ( <mask> . createElement ( 'div' ) ) ; template . content . appendChild ( template2 ) ; const clone = template . cloneNode ( true ) ; return ( // @ts-ignore clone . content . childNodes . length === 0 || // @ts-ignore clone . content . firstChild . content . childNodes . length === 0 ) ; }