code: public function addRepository($name, $config)
      {
          $this->manipulateJson('addRepository', $name, $config, function (&$config, $repo, $repoConfig) {
              // if converting from an array format to hashmap format, and there is a {"packagist.org":false} repo, we have
              // to convert it to "packagist.org": false key on the hashmap otherwise it fails schema validation
              if (isset($config['repositories'])) {
                  foreach ($config['repositories'] as $index => $val) {
                      if ($index === $repo) {
                          continue;
                      }
                      if (is_numeric($index) && ($val === array('packagist' => false) || $val === array('packagist.org' => false))) {
                          unset($config['repositories'][$index]);
                          $config['repositories']['packagist.org'] = false;
                          break;
                      }
                  }
              }
  
              $config['repositories'][$repo] = $repoConfig;
          });
      }
docs: {@inheritdoc}