def METHOD_NAME(self):
    """Test whether the stream data of the model instances have been updated properly
    Apply the migration and then query the raw data of the updated instances. Compare with
    original raw data and check whether all relevant `char1` blocks have been renamed and
    whether ids and other block types are intact.
    """
    self.apply_migration()
    instances = self.model.objects.all().annotate(
        raw_content=Cast(F("content"), JSONField())
    )
    for instance in instances:
        prev_content = self.original_raw_data[instance.id]
        self.assertBlocksRenamed(
            old_content=prev_content, new_content=instance.raw_content
        )