input: from Crypto.Cipher import AES
  
  key = b'Sixteen byte key'
  
  def encrypt(plaintext: str) -> bytes:
      """ Encrypts a given string using AES encryption in ECB mode.
      >>> encrypt("Hello World")
      b'q\xc2\x9d\x9c)p\x92\xb9\x94w\xa7&h\x14Hl'
      """
      cipher = AES.new(key, AES.MODE_ECB)
      return cipher.encrypt(plaintext.encode('utf-8'))
  
  def decrypt(ciphertext: bytes) -> str:
      """ Decrypts a given byte string using AES decryption in ECB mode.
      >>> decrypt(b'q\\xc2\\x9d\\x9c)p\\x92\\xb9\\x94w\\xa7&h\\x14Hl')
      'Hello World'
      """
      cipher = AES.new(key, AES.MODE_ECB)
      return cipher.decrypt(ciphertext).decode('utf-8')
output:     cipher = AES.new(key, AES.MODE_ECB)
      return cipher.decrypt(ciphertext).decode('utf-8')