package org.mercury_im.messenger; import org.mercury_im.messenger.listener.IncomingDirectMessageListener; import org.mercury_im.messenger.entity.chat.Chat; import org.mercury_im.messenger.entity.message.Message; import io.reactivex.Completable; public interface MessageCenter { Messenger getMessenger(); Completable sendMessage(Message message, C chat); void addIncomingMessageListener(IncomingDirectMessageListener listener); }