docs: function getStylingContext(index) {
      var stylingContext = load(index);
      if (!Array.isArray(stylingContext)) {
          var lElement = stylingContext;
          var tNode = lElement.tNode;
          ngDevMode &&
              assertDefined(tNode.stylingTemplate, 'getStylingContext() called before elementStyling()');
          stylingContext = viewData[index + HEADER_OFFSET] =
              allocStylingContext(lElement, tNode.stylingTemplate);
      }
      return stylingContext;
  }