languageCodes property
The language of the supplied audio as a [BCP-47](https://www.rfc-editor.org/rfc/bcp/bcp47.txt) language tag.
Language tags are normalized to BCP-47 before they are used eg "en-us" becomes "en-US". Supported languages for each model are listed in the Table of Supported Models. If additional languages are provided, recognition result will contain recognition in the most likely language detected. The recognition result will include the language tag of the language detected in the audio.
Optional.
Implementation
core.List<core.String>? languageCodes;