private static function createExternalCaFolder($baseFolder)
    {
        // This is hacky, but I can't find a simple way to do this.

        // This process isn't atomic, so give it three tries.
        for ($i = 0; $i < 3; $i++) {
            $path = \tempnam($baseFolder, "dropbox-php-sdk-trusted-certs-empty-dir");
            if ($path === false) {
                throw new \Exception("Couldn't create temp file in folder ".Util::q($baseFolder).".");
            }
            if (!\unlink($path)) {
                throw new \Exception("Couldn't remove temp file to make way for temp dir: ".Util::q($path));
            }
            // TODO: Figure out how to make the folder private on Windows.  The '700' only works on Unix.
            if (!\mkdir($path, 700)) {
                // Someone snuck in between the unlink() and the mkdir() and stole our path.
                throw new \Exception("Couldn't create temp dir: ".Util::q($path));
            }
            \register_shutdown_function(function() use ($path) {
                \rmdir($path);
            });
            return $path;
        }

        throw new \Exception("Unable to create temp dir in ".Util::q($baseFolder).", there's always something in the way.");
    }
private static function createExternalCaFolder($baseFolder)
    {
        // This is hacky, but I can't find a simple way to do this.

        // This process isn't atomic, so give it three tries.
        for ($i = 0; $i < 3; $i++) {
            $path = \tempnam($baseFolder, "dropbox-php-sdk-trusted-certs-empty-dir");
            if ($path === false) {
                throw new \Exception("Couldn't create temp file in folder ".Util::q($baseFolder).".");
            }
            if (!\unlink($path)) {
                throw new \Exception("Couldn't remove temp file to make way for temp dir: ".Util::q($path));
            }
            // TODO: Figure out how to make the folder private on Windows.  The '700' only works on Unix.
            if (!\mkdir($path, 700)) {
                // Someone snuck in between the unlink() and the mkdir() and stole our path.
                throw new \Exception("Couldn't create temp dir: ".Util::q($path));
            }
            \register_shutdown_function(function() use ($path) {
                \rmdir($path);
            });
            return $path;
        }

        throw new \Exception("Unable to create temp dir in ".Util::q($baseFolder).", there's always something in the way.");
    }
@param string $baseFolder

@return string