docs: def get(self, instance, acl):
          """Get an ACL by ID belonging to the instance specified by name.
  
          :param str instance: The name of the instance from which to fetch the ACL.
          :param str acl: The ID of the ACL to fetch.
          :returns: An :py:class:`Acl` object, or None if ACL does not exist.
          :rtype: :py:class:`Acl`
          """
          base_url = self._url.format(instance=instance)
          url = '{base}{aclid}/'.format(base=base_url, aclid=acl)
          response = requests.get(url, **self._default_request_kwargs)
          data = self._get_response_data(response)
          return self._concrete_acl(data)