Trait to allow support of different psr/http-message versions.
Based on the psr-log-aware-trait, developed by Matěj Humpál, K Widholm and Mark Dorison.
By including this shim, you can allow composer to resolve your Psr\Http\Message version for you.
Require the shim.
composer require mpdf/psr-http-message-shim
Modify any use of mpdf's Request.php, Response.php, Stream.php and Uri.php classes to instead use versions from the Mpdf\HttpMessageShim namespace.