'Return the memcache timeout (expiration) for this key.'

def _get_memcache_timeout(self, key, options=None):

    timeout = ContextOptions.memcache_timeout(options)
    if (timeout is None):
        timeout = self._memcache_timeout_policy(key)
    if (timeout is None):
        timeout = ContextOptions.memcache_timeout(self._conn.config)
    if (timeout is None):
        timeout = 0
    return timeout
