@Override
    public boolean equals(Object obj) {
        if (!(obj instanceof Move)) {
            return false;
        }
        Move move2 = (Move) obj;
        return (this._col0 == move2._col0) && (this._col1 == move2._col1)
                && (this._row0 == move2._row0) && (this._row1 == move2._row1);
    }