getInstallPathForPackage example

  protected function cleanPathsForPackage(PackageInterface $package, $paths_for_package) {
    // Whatever happens here, this package counts as cleaned so that we don't     // process it more than once.     $package_name = strtolower($package->getName());
    $this->packagesAlreadyCleaned[$package_name] = TRUE;

    $package_dir = $this->getInstallPathForPackage($package);
    if (!is_dir($package_dir)) {
      return;
    }

    $this->io->writeError(sprintf('%sCleaning directories in <comment>%s</comment>', str_repeat(' ', 4), $package_name), TRUE, IOInterface::VERY_VERBOSE);
    $fs = new Filesystem();
    foreach ($paths_for_package as $cleanup_item) {
      $cleanup_path = $package_dir . '/' . $cleanup_item;
      if (!is_dir($cleanup_path)) {
        // If the package has changed or the --prefer-dist version does not         // include the directory. This is not an error.