code: function() {
          return new Promise((resolve, reject) => {
              console.log(`Removing indexeddb instance: ${this._dbName}`);
              const req = this.indexedDB.deleteDatabase(this._dbName);
  
              req.onblocked = () => {
                  console.log(
                      `can't yet delete indexeddb ${this._dbName}` +
                      ` because it is open elsewhere`,
                  );
              };
  
              req.onerror = (ev) => {
                  // in firefox, with indexedDB disabled, this fails with a
                  // DOMError. We treat this as non-fatal, so that we can still
                  // use the app.
                  console.warn(
                      `unable to delete js-sdk store indexeddb: ${ev.target.error}`,
                  );
                  resolve();
              };
  
              req.onsuccess = () => {
                  console.log(`Removed indexeddb instance: ${this._dbName}`);
                  resolve();
              };
          });
      }
docs: Clear the entire database. This should be used when logging out of a client
  to prevent mixing data between accounts.
  @return {Promise} Resolved when the database is cleared.