6 files declare their use of Request

Installer.php in vendor/composer/composer/src/Composer/Installer.php
PrePoolCreateEvent.php in vendor/composer/composer/src/Composer/Plugin/PrePoolCreateEvent.php
RemoveCommand.php in vendor/composer/composer/src/Composer/Command/RemoveCommand.php
RepositorySet.php in vendor/composer/composer/src/Composer/Repository/RepositorySet.php
RequireCommand.php in vendor/composer/composer/src/Composer/Command/RequireCommand.php
UpdateCommand.php in vendor/composer/composer/src/Composer/Command/UpdateCommand.php