unsupportedLabelEls=[];for(const panelTypeInfo of panelTypeInfos){const labelEl=document.createElement('tab-strip-label');const panel=panelTypeInfo.constructor();const panelType=panel.tagName;Polymer.dom(labelEl).textContent=panel.textLabel;labelEl.panelType=panelType;const supported=panel.supportsModel(this.model);if(this.model&&supported.supported){supportedPanelTypes.push(panelType);Polymer.dom(labelEl).setAttribute('enabled',true);labelEl.addEventListener('click',function(panelType){this.activePanelT...