old_contents: from django.db import models
  
  class Event(models.Model):
      name = models.CharField(max_length=1024, unique=True)
      slug = models.SlugField(max_length=1024)
      
      def __str__(self):
          return self.name
      
  class TimeSlot(models.Model):
      event = models.ForeignKey(Event)
      bookable = models.BooleanField(default=True)
      end = models.DateTimeField()
      name = models.CharField(max_length=1024)
      start = models.DateTimeField()
      
      def __str__(self):
          return "{0} ({1})".format(self.name, self.event)
  
  class Room(models.Model):
      event = models.ForeignKey(Event)
      directions = models.TextField()
      name = models.CharField(max_length=1024)
      
      def __str__(self):
          return "{0} ({1})".format(self.name, self.event)
  
  class Talk(models.Model):
      room = models.ForeignKey(Room, null=True, blank=True)
      timeslot = models.ForeignKey(TimeSlot, null=True, blank=True)
      description = models.TextField()
      slug = models.SlugField(max_length=1024)
      title = models.CharField(max_length=1024, unique=True)
      
      def __str__(self):
          return "{0} in {1}".format(self.title, self.room)
  
new_contents: from django.db import models
  
  class Event(models.Model):
      name = models.CharField(max_length=1024, unique=True)
      slug = models.SlugField(max_length=1024)
      
      def __str__(self):
          return self.name
      
  class TimeSlot(models.Model):
      event = models.ForeignKey(Event)
      bookable = models.BooleanField(default=True)
      end = models.DateTimeField()
      name = models.CharField(max_length=1024)
      start = models.DateTimeField()
      
      def __str__(self):
          return "{0} ({1})".format(self.name, self.event)
  
  class Room(models.Model):
      event = models.ForeignKey(Event)
      directions = models.TextField()
      name = models.CharField(max_length=1024)
      
      def __str__(self):
          return "{0} ({1})".format(self.name, self.event)
  
  class Talk(models.Model):
      room = models.ForeignKey(Room, null=True, blank=True)
      timeslot = models.ForeignKey(TimeSlot, null=True, blank=True)
      description = models.TextField()
      slug = models.SlugField(max_length=1024)
      title = models.CharField(max_length=1024, unique=True)
      
      def __str__(self):
          return "{0} in {1} at {2}".format(self.title, self.room, self.timeslot)
  
subject: Update Talk model __str__ to include time