constructor(options) {
    this.sessionKey = null;
    this.key = options.key;
    this.version = options.version.toString();
  }
Low-level class for encrypting and decrypting payloads.
@class
@param {Object} options - Options for the cipher.
@param {String} options.key localKey of cipher
@param {Number} options.version protocol version
@example
const cipher = new TuyaCipher({key: 'xxxxxxxxxxxxxxxx', version: 3.1})