async def METHOD_NAME(self, db: "AsyncSession"):
    models = []
    schemas = []
    # These ones will be updated
    for i in range(5):
        models.append(await Model.create(db, str_col=f"unit-test-{i}", int_col=i, external_id=f"external-id-{i}"))
        schemas.append(
            ModelCreateSchema(str_col=f"unit-test-{i}-updated", int_col=i * 10, external_id=f"external-id-{i}")
        )
    # This one has to be inserted
    schemas.append(
        ModelCreateSchema(str_col="unit-test-inserted", int_col=99999, external_id="external-id-inserted")
    )
    models = await Model.upsert_many(db, schemas, constraints=[Model.external_id], autocommit=True)
    for i, model in enumerate(models[:5]):
        assert model.str_col == f"unit-test-{i}-updated"
        assert model.int_col == i * 10
    assert models[-1].str_col == "unit-test-inserted"
    assert models[-1].int_col == 99999