Clients can connect to this protocol to subscribe to changes in the set of users linked to this device, as well as the OAuth2 access token associated with each.
This protocol won't be supported on the majority of devices, and shouldn't be used without permission from its maintainers.
Get the set of users linked to this device, and their corresponding access tokens. While the connection to the service remains uninterrumpted, the method call hangs if it would return the same response as the previous time it was called by this client. In other words, if the client already has the most up-to-date credentials, the method acts as a hanging get and only returns when there's an update to report.
The id of a user linked to this device, alongside the current access token to make requests on the user's behalf.
Opaque id for the user with which this credential is associated. It is stable across reconnections to the CredentialsProducer protocol.
OAuth2 access token for this user.