code: function parse_AddinUdf(blob, length, opts) {
  	blob.l += 4; length -= 4;
  	var l = blob.l + length;
  	var udfName = parse_ShortXLUnicodeString(blob, length, opts);
  	var cb = blob.read_shift(2);
  	l -= blob.l;
  	if(cb !== l) throw new Error("Malformed AddinUdf: padding = " + l + " != " + cb);
  	blob.l += cb;
  	return udfName;
  }
docs: /* [MS-XLS] 2.5.1