code: protected FileVerifier getFileVerifier(String pluginId) {
          for (UpdateRepository ur : repositories) {
              if (ur.getPlugin(pluginId) != null && ur.getFileVerfier() != null) {
                  return ur.getFileVerfier();
              }
          }
  
          return new CompoundVerifier();
      }
docs: Gets a file verifier to use for this plugin. First tries to use custom verifier
  configured for the repository, then fallback to the default CompoundVerifier
  
  @param pluginId the plugin we wish to download
  @return FileVerifier instance