final int prime = 31;
        int result = 1;
        result = prime * result + ((value1 == null) ? 0 : value1.hashCode());
        result = prime * result + ((value2 == null) ? 0 : value2.hashCode());
        result = prime * result + ((value3 == null) ? 0 : value3.hashCode());
        result = prime * result + ((value4 == null) ? 0 : value4.hashCode());