public abstract class AType : IComparable<AType>, IEquatable<AType>
    {
        public AType() { DefaultInit(); }
        public AType(string str) { StringInit(str); }


        public int CompareTo([AllowNull] AType other)
        {
            return CompareToImpl(other);
        }

        public bool Equals([AllowNull] AType other)
        {
            return EqualsImpl(other);
        }

        public void SetFromString(string str)
        {
            StringInit(str);
        }

        public override string ToString()
        {
            return ToStringImpl();
        }
        protected abstract int CompareToImpl([AllowNull] AType other);
        protected abstract bool EqualsImpl(AType other);
        protected abstract void DefaultInit();
        protected abstract void StringInit(string str);
        protected abstract string ToStringImpl();

    }