invoke
abstract suspend operator fun invoke(userId: <Error class: unknown class>): Either<CoreFailure, <Error class: unknown class>>
Attempts to find an existing MLS-capable one-on-one conversation, or creates a new one if none is found. In case the conversation already exists, but it's not established yet (see GroupState.ESTABLISHED), it will attempt to join it, returning failure if it fails.
Parameters
userId
The user ID of the other participant.