code: func NewAES256EncrypterEntity(ID string, b bccsp.BCCSP, key, IV []byte) (*BCCSPEncrypterEntity, error) {
  	if b == nil {
  		return nil, errors.New("nil BCCSP")
  	}
  
  	k, err := b.KeyImport(key, &bccsp.AES256ImportKeyOpts{Temporary: true})
  	if err != nil {
  		return nil, errors.WithMessage(err, "bccspInst.KeyImport failed")
  	}
  
  	return NewEncrypterEntity(ID, b, k, &bccsp.AESCBCPKCS7ModeOpts{IV: IV}, &bccsp.AESCBCPKCS7ModeOpts{})
  }
docs: /****************/
  /* Constructors */
  /****************/
  // NewAES256EncrypterEntity returns an encrypter entity that is
  // capable of performing AES 256 bit encryption using PKCS#7 padding.
  // Optionally, the IV can be provided in which case it is used during
  // the encryption; othjerwise, a random one is generated.