new_contents: from django.db import models
  from django.contrib.auth.models import User
  from myhpom import validators
  
  
  def user_pre_save_receiver(sender, instance, **kwargs):
      validators.name_validator(instance.first_name)
      validators.name_validator(instance.last_name)
      validators.email_validator(instance.email)
      if instance.username in [None, '']:
          instance.username = instance.email
  
  
  models.signals.pre_save.connect(user_pre_save_receiver, sender=User)
  
subject: add pre-save validators to the User model