$mockHook->expects( $this->any() )->method( 'onSessionMetadata' )
->will( $this->returnCallback(
function ( SessionBackend $backend, array &$metadata, array $requests ) {
$mockHook->expects( $this->any() )->method( 'onSessionMetadata' )
->will( $this->returnCallback(
function ( SessionBackend $backend, array &$metadata, array $requests ) {