code: def GetDecrypter(cls, encryption_method, **kwargs):
      
      encryption_method = encryption_method.lower()
      decrypter = cls._decrypters.get(encryption_method, None)
      if not decrypter:
        return None
  
      return decrypter(**kwargs)
docs: Retrieves the decrypter object for a specific encryption method.
  
      Args:
        encryption_method (str): encryption method identifier.
        kwargs (dict): keyword arguments depending on the decrypter.
  
      Returns:
        Decrypter: decrypter or None if the encryption method does not exists.
  
      Raises:
        CredentialError: if the necessary credentials are missing.