has
fun hasParticipant(participant: Contact, onCompletion: (Either<Boolean, SippoResourceError>) -> Unit)
Checks if a participant belongs to this group.
Parameters
participant
User to be checked.
on
Callback that will be invoked when the request is completed. In case of success, it will receive true if the user belongs to the group or false if they don't. In case of error, it will receive a SippoResourceError.