Installment Class Mappings using Bson Mappers

InstallmentBsonMap.cs

public class InstallmentMap
    {
        public void Map()
        {
            BsonClassMap.RegisterClassMap<Installment>(map =>
            {
                map.AutoMap();
                map.SetIgnoreExtraElements(true);
                map.MapIdMember(x => x.Id);
                map.MapMember(x => x.Title).SetIsRequired(true);
                map.MapMember(x => x.InstallmentFrequencyInDays).SetIsRequired(true);
                map.MapMember(x => x.DownPayment).SetIsRequired(true);
                map.MapMember(x => x.TotalInstallments).SetIsRequired(true);

            });
        }
    }