code: func AESEncryptWithECB(str, key []byte) ([]byte, error) {
  	cb, err := aes.NewCipher(key)
  	if err != nil {
  		return nil, errors.Trace(err)
  	}
  	mode := newECBEncrypter(cb)
  	return aesEncrypt(str, mode)
  }
docs: // AESEncryptWithECB encrypts data using AES with ECB mode.