DynamoDB nullable date property converter

NullableDatePropertyConverter.cs

using System;

using Amazon.DynamoDBv2.DataModel;
using Amazon.DynamoDBv2.DocumentModel;
    
    public class NullableDatePropertyConverter : IPropertyConverter
    {
        public DynamoDBEntry ToEntry(object value)
        {
            DynamoDBEntry entry = new Primitive {
                Value = null
            };

            if (value != null)
                entry = new Primitive { Value = ((DateTime)value).ToString("o") };

            return entry;
        }

        public object FromEntry(DynamoDBEntry entry)
        {
            var dateTimeString = (entry as Primitive)?.Value.ToString();
            return DateTime.Parse(dateTimeString, null, System.Globalization.DateTimeStyles.RoundtripKind);
        }
    }