[CASE test_model_subtype_relationship_and_getting_and_setting_attributes]
from django.db import models

class A(models.Model):
    pass

class B(models.Model):
    b_attr = 1
    pass

class C(A):
    pass

def service(a: A) -> int:
    pass

a_instance = A()
b_instance = B()
reveal_type(b_instance.b_attr) # E: Revealed type is 'builtins.int'


reveal_type(b_instance.non_existent_attribute) # E: Revealed type is 'Any'
b_instance.non_existent_attribute = 2

service(b_instance)  # E: Argument 1 to "service" has incompatible type "B"; expected "A"

c_instance = C()
service(c_instance)