// check for omitted fields
	zb0001Len := uint32(5)
	var zb0001Mask uint8 /* 5 bits */
	_ = zb0001Mask
	if z.OldDataDir == "" {
		zb0001Len--
		zb0001Mask |= 0x10
	}
	// variable map header, size zb0001Len
	err = en.Append(0x80 | uint8(zb0001Len))
	if err != nil {
		return
	}

	// skip if no fields are to be emitted
	if zb0001Len != 0 {

    static final int ATTR_COMPRESSED = 0x800;
    static final int ATTR_NORMAL = 0x080;
    static final int ATTR_TEMPORARY = 0x100;

    static final int ATTR_GET_MASK = 0x7FFF; /* orig 0x7fff */
    static final int ATTR_SET_MASK = 0x30A7; /* orig 0x0027 */

    static final int DEFAULT_ATTR_EXPIRATION_PERIOD = 5000;

    static final int HASH_DOT = ".".hashCode();