docs: public Blob moveTo(String destBucket, String destBlob) {
      // [START storageMoveFile]
      CopyWriter copyWriter = blob.copyTo(destBucket, destBlob);
      Blob copiedBlob = copyWriter.getResult();
      boolean deleted = blob.delete();
      // [END storageMoveFile]
      if (deleted) {
        return copiedBlob;
      } else {
        return null;
      }
    }