src/Composer/Installer/NoopInstaller.php
public function update(InstalledRepositoryInterface $repo, PackageInterface $initial, PackageInterface $target)
    {
        if (!$repo->hasPackage($initial)) {
            throw new \InvalidArgumentException('Package is not installed: '.$initial);
        }

        $repo->removePackage($initial);
        if (!$repo->hasPackage($target)) {
            $repo->addPackage(clone $target);
        }
    }
public function update(InstalledRepositoryInterface $repo, PackageInterface $initial, PackageInterface $target)
    {
        if (!$repo->hasPackage($initial)) {
            throw new \InvalidArgumentException('Package is not installed: '.$initial);
        }

        $repo->removePackage($initial);
        if (!$repo->hasPackage($target)) {
            $repo->addPackage(clone $target);
        }
    }
{@inheritDoc}