public override DateTime DeserializeImpl(TSource source, SerializationContext context)
        {
            context.StartGroup(Tag); // will be ended internally
            DateTime value = ProtoTimeSpan.DeserializeDateTime(context);

            return(value);
        }
        public override DateTime DeserializeImpl(TSource source, SerializationContext context)
        {
            long     restore = context.LimitByLengthPrefix();
            DateTime value   = ProtoTimeSpan.DeserializeDateTime(context);

            context.MaxReadPosition = restore;
            return(value);
        }