src/Composer/Installer/InstallationManager.php
public function markAliasUninstalled(RepositoryInterface $repo, MarkAliasUninstalledOperation $operation)
    {
        $package = $operation->getPackage();

        $repo->removePackage($package);
    }
public function markAliasUninstalled(RepositoryInterface $repo, MarkAliasUninstalledOperation $operation)
    {
        $package = $operation->getPackage();

        $repo->removePackage($package);
    }
Executes markAlias operation.

@param RepositoryInterface           $repo      repository in which to check
@param MarkAliasUninstalledOperation $operation operation instance