private void doUploadFromByteArrayTest(
      CloudPageBlob blob, int bufferSize, int bufferOffset, int count) throws Exception {
    byte[] buffer = BlobTestHelper.getRandomBuffer(bufferSize);
    byte[] downloadedBuffer = new byte[bufferSize];

    blob.uploadFromByteArray(buffer, bufferOffset, count);
    blob.downloadToByteArray(downloadedBuffer, 0);

    int i = 0;
    for (; i < count; i++) {
      assertEquals(buffer[i + bufferOffset], downloadedBuffer[i]);
    }

    for (; i < downloadedBuffer.length; i++) {
      assertEquals(0, downloadedBuffer[i]);
    }
  }