* allow for separate processes to use and refresh access tokens. The process
* that uses the access token (post) has an error if the token is expired; the
* process that refreshes the access token (send) must have already refreshed if
* the expiration is close.
*
* allow for separate processes to use and refresh access tokens. The process
* that uses the access token (post) has an error if the token is expired; the
* process that refreshes the access token (send) must have already refreshed if
* the expiration is close.
*