public enum Operator {
    GREATER_THAN,
    LESS_THEN;
    int getImageResourceId(){
        int id = 0;
        // Operator operator = this;
        if (this == GREATER_THAN){
            id = 1;
        }
        if (this == LESS_THEN){
            id = 2;
        }
        return id;
    }
}