| 1234567891011121314151617181920212223 | import { isShadowRoot } from "./instanceOf.js";export default function contains(parent, child) {  var rootNode = child.getRootNode && child.getRootNode(); // First, attempt with faster native method  if (parent.contains(child)) {    return true;  } // then fallback to custom implementation with Shadow DOM support  else if (rootNode && isShadowRoot(rootNode)) {      var next = child;      do {        if (next && parent.isSameNode(next)) {          return true;        } // $FlowFixMe[prop-missing]: need a better way to handle this...        next = next.parentNode || next.host;      } while (next);    } // Give up, the result is false  return false;}
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