          ("title", models.CharField(max_length=200)),
      ])
      book_migrations_fk = ModelState("otherapp", "Book", [
          ("id", models.AutoField(primary_key=True)),
          ("author", models.ForeignKey("migrations.UnmigratedModel")),
          ("title", models.CharField(max_length=200)),
      ])
      book_with_no_author = ModelState("otherapp", "Book", [
          ("id", models.AutoField(primary_key=True)),
          ("title", models.CharField(max_length=200)),
 
</s> remove         ("author", models.ForeignKey("thirdapp.AuthorProxy")),
 </s> add         ("author", models.ForeignKey("thirdapp.AuthorProxy", models.CASCADE)), </s> remove         ("author", models.ForeignKey("testapp.Writer")),
 </s> add         ("author", models.ForeignKey("testapp.Writer", models.CASCADE)), </s> remove         ("writer", models.ForeignKey("testapp.Writer")),
 </s> add         ("writer", models.ForeignKey("testapp.Writer", models.CASCADE)), </s> remove         ("author", models.ForeignKey("testapp.Author")),
 </s> add         ("author", models.ForeignKey("testapp.Author", models.CASCADE)), </s> remove         ("author", models.ForeignKey("testapp.Author")),
 </s> add         ("author", models.ForeignKey("testapp.Author", models.CASCADE)),
        ("author", models.ForeignKey("migrations.UnmigratedModel", models.CASCADE)),
          ("title", models.CharField(max_length=200)),
      ])
      book_migrations_fk = ModelState("otherapp", "Book", [
          ("id", models.AutoField(primary_key=True)),
        ("author", models.ForeignKey("migrations.UnmigratedModel", models.CASCADE)),
          ("title", models.CharField(max_length=200)),
      ])
      book_with_no_author = ModelState("otherapp", "Book", [
          ("id", models.AutoField(primary_key=True)),
          ("title", models.CharField(max_length=200)),
keep keep keep keep replace keep keep keep keep keep
 Fixed #21127 -- Started deprecation toward requiring on_delete for ForeignKey/OneToOneField 
tests/migrations/test_autodetector.py