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'\x00)\xa7S\x02\xdfT4B\xd1\\\\5\x16\xfcO'
      """
      cipher = AES.new(key, AES.MODE_ECB)
      return cipher.encrypt(plaintext.encode())
  
  def decrypt(ciphertext: bytes) -> str:
      """ Decrypts a given ciphertext using AES decryption in ECB mode.
      >>> decrypt(b'\x00)\xa7S\x02\xdfT4B\xd1\\\\5\x16\xfcO')
      'Hello World'
      """
      cipher = AES.new(key, AES.MODE_ECB)
      return cipher.decrypt(ciphertext).decode()
output:     cipher = AES.new(key, AES.MODE_ECB)
      return cipher.decrypt(ciphertext).decode()