updateLastMessage method 
    
      
  
dynamic
updateLastMessage(
 - BaseMessage message
)override
     
    
    
  Implementation
  @override
updateLastMessage(BaseMessage message) async {
  int matchingIndex = getMatchingIndexFromKey(message.conversationId!);
  if (matchingIndex != -1) {
    Conversation conversation = list[matchingIndex];
    conversation.lastMessage = message;
    conversation.unreadMessageCount = 0;
    removeElementAt(matchingIndex);
    addElement(conversation);
  } else {
    final conversation =
        await CometChatHelper.getConversationFromMessage(message);
    if (conversation != null) {
      addElement(conversation);
    }
  }
}