}

    @Override
    public String toString() {
      return "Functions.toStringFunction()";
    }
  }

  /**
   * Returns the identity function.
   *
   * <p><b>Discouraged:</b> Prefer using a lambda like {@code v -> v}, which is shorter and often
   * more readable.
   */
  // implementation is "fully variant"; E has become a "pass-through" type
  @SuppressWarnings("unchecked")

    }

    @Override
    public String toString() {
      return "Functions.toStringFunction()";
    }
  }

  /**
   * Returns the identity function.
   *
   * <p><b>Discouraged:</b> Prefer using a lambda like {@code v -> v}, which is shorter and often
   * more readable.
   */
  // implementation is "fully variant"; E has become a "pass-through" type
  @SuppressWarnings("unchecked")