'Get/set/modify the Cache-Control header (`HTTP spec section 14.9
<http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9>`_)'

def _cache_control__get(self):

    value = self.headers.get('cache-control', '')
    if (self._cache_control_obj is None):
        self._cache_control_obj = CacheControl.parse(value, updates_to=self._update_cache_control, type='response')
        self._cache_control_obj.header_value = value
    if (self._cache_control_obj.header_value != value):
        new_obj = CacheControl.parse(value, type='response')
        self._cache_control_obj.properties.clear()
        self._cache_control_obj.properties.update(new_obj.properties)
        self._cache_control_obj.header_value = value
    return self._cache_control_obj
