validation.cs

namespace EBT.SOF.DTO
{
    public class SessionDto
    {
        public long Id { get; set; }

        ....

        public ValidationResultDto ValidationResult { get; set; }
    }
    
    
    public class ValidationResultDto
    {
        public bool IsValid { get; set; }

        public List<ValidationMessageDto> Errors { get; set; }

        public List<ValidationMessageDto> Warnings { get; set; }
    }


    public class ValidationMessageDto
    {
        public string Type { get; set; }

        public string Message { get; set; }
    }
}