Get an ObjectRocket instance by name.

        :param str instance_name: The name of the instance to retrieve.
        :returns: A subclass of :py:class:`bases.BaseInstance`, or None if instance does not exist.
        :rtype: :py:class:`bases.BaseInstance`

def get(self, instance_name):
        """Get an ObjectRocket instance by name.

        :param str instance_name: The name of the instance to retrieve.
        :returns: A subclass of :py:class:`bases.BaseInstance`, or None if instance does not exist.
        :rtype: :py:class:`bases.BaseInstance`
        """
        url = self._url + instance_name + '/'
        response = requests.get(url, **self._default_request_kwargs)
        data = self._get_response_data(response)
        return self._concrete_instance(data)