This is a basic demo using Spring WebFlux and Reactive Repositories with
Google Cloud Firestore.
Firestore Control Panel
This section allows you to read and modify User entities in Firestore.
Some values are prefilled as an example of what you can type in.
Create and save a new User
Show all users with age
Show phone numbers by name (even if a user is removed, the associated phone numbers remain - because they are stored as a subcollection)
Remove user by name
Remove phone numbers by user name