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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 publish(self, cart, env=None):
 """ `cart` - Release cart to publish in json format Publish a release cart in JSON format to the pre-release environment. """

        juicer.utils.Log.log_debug("Initializing publish of cart '%s'" % cart.cart_name)

        if not env:
            env = self._defaults['start_in']

        cart_id = juicer.utils.upload_cart(cart, env)
        juicer.utils.Log.log_debug('%s uploaded with an id of %s' %
                                   (cart.cart_name, cart_id))
        return True