protected static final int ATTR_GET_MASK = 0x7FFF;
    /**
     * Mask for attributes that can be set on the server
     */
    protected static final int ATTR_SET_MASK = 0x30A7;
    /**
     * Default expiration period for cached attributes in milliseconds
     */
    protected static final int DEFAULT_ATTR_EXPIRATION_PERIOD = 5000;

    /**
     * Hash code for the "." directory entry
     */