code: @Override
  	public boolean apply(final WarcRecord x) {
  		Header s = x.getWarcHeader(WarcHeader.Name.WARC_PAYLOAD_DIGEST);
  		return s != null && Arrays.equals(digest, Util.fromHexString(s.getValue()));
  	}
docs: Apply the filter to a given WarcRecord
  
  @param x the WarcRecord to be filtered
  @return <code>true</code> if the <code>WarcHeader.Name.WARC_PAYLOAD_DIGEST</code> of the <code>WarcHeader</code> of <code>x</code> is not null and equal to the inner digest (hexadecimal comparison)