text: from django.db import models
  from django.contrib.auth.models import AbstractUser
  
  
  class User(AbstractUser):
      pass
  
  
  class Book(models.Model):
      gid = models.CharField(max_length=300)
      started = models.DateField(null=True)
      finished = models.DateField(null=True)
      user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='readingList')
  