Group results. There exists an element for each existing unique combination of property/values. The element contains a count for the number of times those specific property/values appear.
A timestamp in RFC3339 UTC "Zulu" format, with nanosecond resolution and up to nine fractional digits. Examples: "2014-10-02T15:01:23Z" and "2014-10-02T15:01:23.045123456Z".
nextPageToken
string
Token to retrieve the next page of results, or empty if there are no more results.