
 ?÷     m being instantiated by simply
     * deactivating the installer for them. This ensure that no third-party
     * code is ever executed.
     */
    public function disablePlugins()
    {
        foreach ($this->installers as $i => $installer) {
            if (!$installer instanceof PluginInstaller) {
                continue;
            }

            unset($this->installers[$i]);
        }
    }

    /**
     * Returns installer for a specific package type.
     *
     * @param string $type package type
     *
     * @throws \InvalidArgumentException if installer for provided type is not registered
     * @return InstallerInterface
     */
    public function getInstaller($type)
    {
        $type = strtolower($type);

        if (isset($this->cache[$type])) {
            return $this->cache[$type];
        }

        foreach ($this->installers as $installer) {
            if ($installer->supports($type)) {
                return $this->cache[$type] = $installer;
            }
        }

        throw new \InvalidArgumentException('Unknown installer type: '.$type);
    }

    /**
     * Checks whether provided package is installed in one of the registered installers.
     *
     * @param InstalledRepositoryInterface $repo    repository in which to check
     * @param PackageInterface             $package package instance
     *
     * @return bool
     */
    public function isPackageInstalled(InstalledRepositoryInterface $repo, PackageInterface $package)
    {
        if ($package instanceof AliasPackage) {
            return $repo->hasPackage($package) && $this->isPackageInstalled($repo, $package->getAliasOf());
        }

        return $this->getInstaller($package->getType())->isInstalled($repo, $package);
    }

    /**
     * Install binary for the given package.
     * If the installer associated to this package doesn't handle that function, it'll do nothing.
     *
     * @param PackageInterface $package Package instance
     */
    public function ensureBinariesPresence(PackageInterface $package)
    {
        try {
            $installer = $this->getInstaller($package->getType());
        } catch (\InvalidArgumentException $e) {
            // no installer found for the current package type (@see `getInstaller()`)
            return;
        }

        // if the given installer support installing binaries
        if ($installer instanceof BinaryPresenceInterface) {
            $installer->ensureBinariesPresence($package);
        }
    }

    /**
     * Executes solver operation.
     *
     * @param RepositoryInterface $repo      repository in which to check
     * @param OperationInterface  $operation operation instance
     */
    public function execute(RepositoryInterface $repo, OperationInterface $operation)
    {
        $method = $operation->getJobType();
        $this->$method($repo, $operation);
    }

    /**
     * Executes install operation.
     *
     * @param RepositoryInterface $repo      repository in which to check
     * @param InstallOperation    $operation operation instance
     */
    public function install(RepositoryInterface $repo, InstallOperation $operation)
    {
        $package = $operation->getPackage();
        $installer = $this->getInstaller($package->getType());
        $installer->install($repo, $package);
        $this->markForNotification($package);
    }

    /**
     * Executes update operation.
     *
     * @param RepositoryInterface $repo      repository in which to check
     * @param UpdateOperation     $operation operation instance
     */
    public function update(RepositoryInterface $repo, UpdateOperation $operation)
    {
        $initial = $operation->getInitialPackage();
        $target = $operation->getTargetPackage();

        $initialType = $initial->getType();
        $targetType = $target->getType();

        if ($initialType === $targetType) {
            $installer = $this->getInstaller($initialType);
            $installer->update($repo, $initial, $target);
            $this->markForNotification($target);
        } else {
            $