If you have more than one copy of React DevTools installed and enabled (e.g. the version in the Chrome store and a locally built version) they can interfere with each other.

DevTools should detect this case and warn by showing a dialog in the DevTools UI and/or by logging to the console.

Note that we _should not warn_ if a related tool like Fast Refresh is present, only another copy of DevTools.
return +str + '' === str;
}
function installContentScript(tabId: number) {
  chrome.tabs.executeScript(
    tabId,
    {file: '/build/contentScript.js'},
    function() {},
  );
}
function doublePipe(one, two) {
  one.onMessage.addListener(lOne);
  function lOne(message) {
    two.postMessage(message);
  }
  two.onMessage.addListener(lTwo);
  function lTwo(message) {