from django.db import modelstry:    # BUG: CWE-312 Cleartext Storage of Sensitive Information    # from django.contrib.auth.models import AbstractUser    # FIXED:     from django.contrib.auth.models import AbstractUser, UserManagerexcept ImportError:    from django.db.models import Model as AbstractUserclass CustomUser(AbstractUser):    extra_field = models.CharField(max_length=2)    new_username_field = models.CharField('userid', unique=True, max_length=20)    USERNAME_FIELD = 'new_username_field'    def save(self, *args, **kwargs):        self.new_username_field = self.username        super(CustomUser, self).save(*args, **kwargs)class PhoneNumberUser(CustomUser):    phone_number = models.CharField(max_length=11, default="+15555555")class NoUsernameUser(models.Model):    """User model without a "username" field for authentication    backend testing    """    pass