code: public com.google.privacy.dlp.v2.TransientCryptoKeyOrBuilder getTransientOrBuilder() {
      if (sourceCase_ == 1) {
        return (com.google.privacy.dlp.v2.TransientCryptoKey) source_;
      }
      return com.google.privacy.dlp.v2.TransientCryptoKey.getDefaultInstance();
    }
docs: <code>.google.privacy.dlp.v2.TransientCryptoKey transient = 1;</code>