endUserMetadata property
Information about the end-user to improve the relevance and accuracy of generative answers.
This will be interpreted and used by a language model, so, for good
results, the data should be self-descriptive, and in a simple structure.
Example: json { "subscription plan": "Business Premium Plus", "devices owned": [ {"model": "Google Pixel 7"}, {"model": "Google Pixel Tablet"} ] } 
Optional.
The values for Object must be JSON objects. It can consist of num,
String, bool and null as well as Map and List values.
Implementation
core.Map<core.String, core.Object?>? endUserMetadata;