code: def get_primary_contributors(self, permitted=True):
          
          primary_credits = []
          credits = self.credits.exclude(role=None).order_by('role')
          if credits:
              primary_role = credits[0].role
              for credit in credits:
                  if credit.role == primary_role:
                      primary_credits.append(credit)
  
          contributors = []
          for credit in primary_credits:
              contributor = credit.contributor
              if permitted and contributor.is_permitted:
                  contributors.append(contributor)
              else:
                  contributors.append(contributor)
  
          return contributors
docs: Returns a list of primary contributors, with primary being defined as those contributors that have the highest role assigned(in terms of priority). When permitted is set to True only permitted contributors are returned.