code: private static String createBaseUrl(AuthleteConfiguration configuration)
      {
          String baseUrl = configuration.getBaseUrl();
  
          // If the configuration does not contain a base URL.
          if (baseUrl == null)
          {
              throw new IllegalArgumentException("The configuration does not have information about the base URL.");
          }
  
          try
          {
              // Check whether the format of the given URL is valid.
              new URL(baseUrl);
          }
          catch (MalformedURLException e)
          {
              // The format of the base URL is wrong.
              throw new IllegalArgumentException("The base URL is malformed.", e);
          }
  
          if (baseUrl.endsWith("/"))
          {
              // Drop the '/' at the end of the URL.
              return baseUrl.substring(0, baseUrl.length() - 1);
          }
          else
          {
              // Use the value of the base URL without modification.
              return baseUrl;
          }
      }
docs: Get 'Base URL' from the configuration. If the base URL ends with '/',
  it is dropped.