EnvelopeGenerator/EnvelopeGenerator.Domain/Interfaces/IEnvelope.cs

namespace EnvelopeGenerator.Domain.Interfaces
{
    public interface IEnvelope
    {
        int? EnvelopeTypeId { get; set; }

        byte[]
#if nullable
            ?
#endif
            DocResult { get; }
    }

    public static class EnvelopeExtensions
    {
        public static bool IsReadAndConfirm(this IEnvelope envelope)
        {
            return envelope.EnvelopeTypeId == 2;
        }

        public static bool IsReadAndSign(this IEnvelope envelope)
        {
            return envelope.EnvelopeTypeId != 2;
        }

        public static bool IsBurned(this IEnvelope envelope)
        {
            return envelope.DocResult != null;
        }
    }
}