def change_object_content_type(self, obj, new_ctype, guess=False):
        """
        Copies object to itself, but applies a new content-type. The guess
        feature requires this container to be CDN-enabled. If not, then the
        content-type must be supplied. If using guess with a CDN-enabled
        container, new_ctype can be set to None. Failure during the put will
        result in an exception.
        """
        return self.manager.change_object_content_type(self, obj, new_ctype,
                guess=guess)
Copies object to itself, but applies a new content-type. The guess
        feature requires this container to be CDN-enabled. If not, then the
        content-type must be supplied. If using guess with a CDN-enabled
        container, new_ctype can be set to None. Failure during the put will
        result in an exception.