wp-includes/PHPMailer/OAuth.php:124Generate a base64-encoded OAuth token.
string public function getOauth64() { //Get a new token if it's not available or has expired if (null === $this->oauthToken || $this->oauthToken->hasExpired()) { $this->oauthToken = $this->getToken(); } return base64_encode( 'user=' . $this->oauthUserEmail . "\001auth=Bearer " . $this->oauthToken . "\001\001" ); }Unchanged from 6.9.7 through 7.1.0.
Signature, return type and hooks compared across 3 parsed releases.
src/wp-includes/PHPMailer/OAuth.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.