How to use the @taquito/http-utils.STATUS_CODE.NOT_FOUND function in @taquito/http-utils

async publicKey(): Promise {
    try {
      const { public_key } = await this.http.createRequest({
        url: this.createURL(`/keys/${this.pkh}`),
        method: 'GET',
      });
      return public_key;
    } catch (ex) {
      if (ex instanceof HttpResponseError) {
        if (ex.status === STATUS_CODE.NOT_FOUND) {
          throw new KeyNotFoundError(`Key not found: ${this.pkh}`, ex);
        }
      }
      throw ex;
    }
  }