from django.db import models

from django.db.models import Q

from django.utils.translation import ugettext_lazy as _

from django.utils.timezone import now

from django.contrib.auth.models import User

import reversion

from markitup.fields import MarkupField

from model_utils.managers import InheritanceManager

        return self.speaker.email

    @property

    def number(self):

        return str(self.pk).zfill(3)

    def speakers(self):

        yield self.speaker

        speakers = self.additional_speakers.exclude(

            additionalspeaker__status=AdditionalSpeaker.SPEAKING_STATUS_DECLINED)

        for speaker in speakers:

            yield speaker