code: public static Smartsheet createDefaultClient() {
          String accessToken = System.getenv("SMARTSHEET_ACCESS_TOKEN");
          SmartsheetImpl smartsheet = new SmartsheetImpl(DEFAULT_BASE_URI, accessToken);
          return smartsheet;
      }
docs: <p>Creates a Smartsheet client with default parameters. SMARTSHEET_ACCESS_TOKEN
  must be set in the environment.</p>
  
  @return the Smartsheet client