function createStore(dbName, storeName) {
  const dbp = idbReady().then(() => {
    const request = indexedDB.open(dbName);
    
    // Log #1
    console.log(request);
    request.onupgradeneeded = () => {
      // Log #2 is never called
      console.log("Create store", request.result);
      request.result.createObjectStore(storeName);
    };
    // Log #3
    console.warn("onupgradeneeded?");
    return promisifyRequest(request);
  });
  return (txMode, callback) =>
    dbp.then((db) => {
      callback(db.transaction(storeName, txMode).objectStore(storeName));
    });
}

// This handler is called when a new version of the database
// is created, either when one has not been created before
// or when a new version number is submitted by calling
// window.indexedDB.open().
// This handler is only supported in recent browsers.
request.onupgradeneeded = function(event) {
  var db = event.target.result;
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