src/Composer/Installer/NoopInstaller.php
public function install(InstalledRepositoryInterface $repo, PackageInterface $package)
    {
        if (!$repo->hasPackage($package)) {
            $repo->addPackage(clone $package);
        }
    }
public function install(InstalledRepositoryInterface $repo, PackageInterface $package)
    {
        if (!$repo->hasPackage($package)) {
            $repo->addPackage(clone $package);
        }
    }
{@inheritDoc}