Django остальные рамки TestCase не проверяет ключ Foreing

Question

Я использую python 3.5 и Django 3.0.5 и пытаюсь протестировать мое приложение в tests.py, но появилась ошибка.

Ошибка

cls.subcategoria = SubCategoria.objects.create(id=7, descripcion='Desarrollo Web test', categoria_id=categoria)
NameError: name 'categoria' is not defined

Вот мой код:

from django.db import models

class Categoria(models.Model):
descripcion = models.CharField(
    max_length=100,
    help_text='Descripción de la Categoría',
    unique=True
)

def __str__(self):
    return '{}'.format(self.descripcion)

class Meta:
    verbose_name_plural = "Categorías"


class SubCategoria(models.Model):
categoria = models.ForeignKey(Categoria, on_delete=models.CASCADE)
descripcion = models.CharField(
    max_length=100,
    help_text='Descripción de la Sub Categoría'
)

def __str__(self):
    return '{}:{}'.format(self.categoria.descripcion,self.descripcion)

class Meta:
    verbose_name_plural = "Sub Categorías"
    unique_together = ('categoria','descripcion')

class Producto(models.Model):
subcategoria = models.ForeignKey(SubCategoria, on_delete=models.CASCADE)
descripcion = models.CharField(
    max_length=100,
    help_text='Descripción del Producto',
    unique=True
)
fecha_creado = models.DateTimeField()
vendido = models.BooleanField(default=False)

def __str__(self):
    return self.descripcion  

class Meta:
    verbose_name_plural = "Productos"


from django.contrib.auth.models import User, AnonymousUser
from django.test import RequestFactory
from django.urls import reverse, resolve
from mixer.backend.django import mixer
from app.apiviews import ProductoDetalle
from app.models import Producto, SubCategoria, Categoria
from django.test import TestCase
import pytest
import datetime


class TestUrls(TestCase):
def test_detail_url(self):
    path = reverse('producto_detalle', kwargs={'pk':1})
    assert resolve(path).view_name == 'producto_detalle'


class TestModelsCase(TestCase):

@classmethod
def setUpTestData(cls):
    #Set up non-modified objects used by all test methods
    cls.categoria = Categoria.objects.create(id=7, descripcion='Test Django')               
    cls.subcategoria = SubCategoria.objects.create(id=7, descripcion='Desarrollo Web test', categoria_id=categoria)        
    cls.prodc = Producto.objects.create(id=7, descripcion='django 3.0', fecha_creado=datetime.now.today(), vendido=False, subcategoria_id=subcategoria)


def test_alice_first_name(self):
   self.assertEqual(self.categoria.id,7)

Сообщение об ошибке

(venv) λ python manage.py test
Creating test database for alias 'default'...
System check identified no issues (0 silenced).
E.
======================================================================
ERROR: setUpClass (core.test.test_models.TestModelsCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Workspace\workspace_python\Project_Products\venv\lib\site-packages\django\test\testcases.py", line 1137, in setUpClass
    cls.setUpTestData()
  File "C:\Workspace\workspace_python\Project_Products\core\test\test_models.py", line 24, in setUpTestData
    cls.subcategoria = SubCategoria.objects.create(id=7, descripcion='Desarrollo Web test', categoria_id=categoria)
NameError: name 'categoria' is not defined

----------------------------------------------------------------------
Ran 1 test in 0.018s

    enter code here

FAILED (errors=1)
Destroying test database for alias 'default'...