old_contents: from django.contrib.auth.models import User
  from django.db import models
  from django.db.models.signals import post_save
  from channels import Group
  
  from balarco import utils
  
  
  class UserProfile(models.Model):
      user = models.OneToOneField(User)
      profile_picture = models.ImageField(upload_to='media/profile_pictures')
  
  
  def save_profile(sender, instance, **kwargs):
      """Sends a notification to the user.
      """
      notification = {
          'notif_type': utils.NOTIF_TYPE_USERS_TABLE_CHANGE,
          'text': "Se ha actualizado la tabla de usuarios",
      }
      Group('users-table').send({
          'text': json.dumps(notification),
          })
  
  
  post_save.connect(save_profile, sender=User)
  
new_contents: import json
  
  from django.contrib.auth.models import User
  from django.db import models
  from django.db.models.signals import post_save
  from channels import Group
  
  from balarco import utils
  
  
  class UserProfile(models.Model):
      user = models.OneToOneField(User)
      profile_picture = models.ImageField(upload_to='media/profile_pictures')
  
  
  def save_profile(sender, instance, **kwargs):
      """Sends a notification to the user.
      """
      notification = {
          'notif_type': utils.NOTIF_TYPE_USERS_TABLE_CHANGE,
          'text': "Se ha actualizado la tabla de usuarios",
      }
      Group('users-table').send({
          'text': json.dumps(notification),
          })
  
  
  post_save.connect(save_profile, sender=User)
  
subject: Fix import error 2