joinConversation method
Implementation
@override
Future<Conversation> joinConversation(
JoinConversationParams params) async {
final conversation = Conversation(
id: 'conv-${DateTime.now().millisecondsSinceEpoch}',
type: ConversationType.group,
mode: ConversationMode.ephemeral,
name: params.displayName,
);
_conversations[conversation.id] = conversation;
_messages[conversation.id] = [];
return conversation;
}