docs: function openDatabase() {
      return new Promise((resolve, reject) => {
        var request = indexedDB.open(dbName, dbVersion);
        request.onerror = reject.bind(null, 'Error opening wasm cache database');
        request.onsuccess = () => { resolve(request.result) };
        request.onupgradeneeded = event => {
          var db = request.result;
          if (db.objectStoreNames.contains(storeName)) {
              console.log(`Clearing out version ${event.oldVersion} wasm cache`);
              db.deleteObjectStore(storeName);
          }
          console.log(`Creating version ${event.newVersion} wasm cache`);
          db.createObjectStore(storeName)
        };
      });
    }