请给我一些解决以下错误的方法。这是一个聊天应用....代码和错误如下::conversations_controller.rbdefcreateifConversation.between(params[:sender_id],params[:recipient_id]).present?@conversation=Conversation.between(params[:sender_id],params[:recipient_id]).firstelse@conversation=Conversation.create!(conversation_params)endrenderj