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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def change_object_content_type(self, container, obj, new_ctype, guess=False):
 """ Copies object to itself, but applies a new content-type. The guess feature requires the 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. """

        cname = utils.get_name(container)
        oname = utils.get_name(obj)
        if guess and container.cdn_enabled:
            # Test against the CDN url to guess the content-type.
            obj_url = "%s/%s" % (container.cdn_uri, oname)
            new_ctype = mimetypes.guess_type(obj_url)[0]
        return self.copy_object(container, obj, container,
                content_type=new_ctype)