class StaticHolder {
    private static AviatorEvaluatorInstance INSTANCE =
        new AviatorEvaluatorInstance(Options.getDefaultEvalMode().evalMode);
  }

  /**
   * Get the default evaluator instance
   *
   * @since 4.0.0
   * @return
   */
  public static AviatorEvaluatorInstance getInstance() {
    return StaticHolder.INSTANCE;
  }

  /**
   * A helper method to generate a env object. The arguments should be a sequence of pair <String,
   * Object>.
   *
   * @since 4.2.9
   * @param args
   * @return A new env instance contains arguments.
   */
  public static Map<String, Object> newEnv(final Object... args) {<FILL_FUNCTION_BODY>

    if (args != null && args.length % 2 != 0) {
      throw new IllegalArgumentException("Expect arguments number is even.");
    }
    Map<String, Object> env =
        (args != null && args.length <= 16) ? new ArrayHashMap<String, Object>()
            : new HashMap<String, Object>(args != null ? args.length : 16);

    if (args != null) {
      for (int i = 0; i < args.length; i += 2) {
        String key = (String) args[i];
        env.put(key, args[i + 1]);
      }
    }
    return env;
  
<no_super_class>