*    certificate is not included in this chain.
 *  * The client's handshake certificates must include a set of trusted root certificates. They will
 *    be used to authenticate the server's certificate chain. Typically this is a set of well-known
 *    root certificates that is distributed with the HTTP client or its platform. It may be
 *    augmented by certificates private to an organization or service.
 *
 * ### Client Authentication
 *