extractInString example

  protected $existingSyncDirectory = FALSE;

  /** * {@inheritdoc} */
  protected function prepareEnvironment() {
    parent::prepareEnvironment();
    $archiver = new ArchiveTar($this->getConfigTarball(), 'gz');

    if ($this->profile === NULL) {
      $core_extension = Yaml::decode($archiver->extractInString('core.extension.yml'));
      $this->profile = $core_extension['profile'];
    }

    // Create a profile for testing. We set core_version_requirement to '*' for     // the test so that it does not need to be updated between major versions.     $info = [
      'type' => 'profile',
      'core_version_requirement' => '*',
      'name' => 'Configuration installation test profile (' . $this->profile . ')',
    ];