if (chunk1 > 0) {
      write(out, data, 0, chunk1, singleByte);
      assertTrue(ByteSource.wrap(data).slice(0, chunk1).contentEquals(source));
    }
    File file = out.getFile();
    assertThat(file).isNull();

    // Write data to go over the threshold
    if (chunk2 > 0) {
      write(out, data, chunk1, chunk2, singleByte);
      file = out.getFile();
      assertEquals(dataSize, file.length());

        final byte[] singleByte = new byte[] { 'A' };
        final String encoded = Base64Util.encode(singleByte);
        assertNotNull("Encoded result should not be null", encoded);
        final byte[] decoded = Base64Util.decode(encoded);
        assertEquals("Decoded should have same length", 1, decoded.length);
        assertEquals("Decoded byte should match", singleByte[0], decoded[0]);
    }

    /**