Proposal before being

Proposal.cs

public class Proposal : Entity
{
    public Guid CandidateId { get; }
    public Guid JobListingId { get; }
    public ProposaStatus Status { get; private set; }
    public DateTime? ClosedAt { get; private set; }

    public Proposal(Guid candidateId, Guid jobListingId)
    {
        CandidateId = candidateId;
        JobListingId = jobListingId;
        Status = ProprosalStatus.Open;
    }
    
    public void Accept()
    {
        ChangeStatus(ProposalStatus.Accepted);
        base.EventsRaised.Add(new ProposalAcceptedEvent(proposal.Id, proposal.AcceptedAt))
    }

    public void Deny()
    {
        ChangeStatus(ProposalStatus.Denied);
        base.EventsRaised.Add(new ProposalDeniedEvent(proposal.Id, proposal.AcceptedAt))
    }

    private void ChangeStatus(ProposalStatus newStatus)
    {
        if(DateTime.Now.Substract(proprosal.SentAt).TotalDays > 15)
            throw new DomainException("This proprosal has expired");
        
        if(Status != ProposalStatus.Pending)
            throw new DomainException("Cannot accept or deny this proposal");

        Status = newStatus;
        ClosedAt = DateTime.Now;
    }
}