Add supporting themes required for Lotusdocs

themes/hugo-mod-jslibs-dist/popperjs/package/lib/dom-utils/instanceOf.js

@@ -0,0 +1,23 @@
+import getWindow from "./getWindow.js";
+
+function isElement(node) {
+  var OwnElement = getWindow(node).Element;
+  return node instanceof OwnElement || node instanceof Element;
+}
+
+function isHTMLElement(node) {
+  var OwnElement = getWindow(node).HTMLElement;
+  return node instanceof OwnElement || node instanceof HTMLElement;
+}
+
+function isShadowRoot(node) {
+  // IE 11 has no ShadowRoot
+  if (typeof ShadowRoot === 'undefined') {
+    return false;
+  }
+
+  var OwnElement = getWindow(node).ShadowRoot;
+  return node instanceof OwnElement || node instanceof ShadowRoot;
+}
+
+export { isElement, isHTMLElement, isShadowRoot };