package com.example.cosmos_serversb.models; import java.lang.reflect.Array; import java.util.*; import javax.inject.Singleton; import com.example.cosmos_serversb.entities.*; enum Respo{ aaa } @Singleton public class Groups { private static Groups thaInstance = null; private ArrayList<Group> accounts = new ArrayList<>(); private Groups(){ } public static Groups getInstance(){ if(thaInstance == null){ thaInstance = new Groups(); } return thaInstance; } public HashMap<String, String> groupsListByUid(String uId, String token){ return null; } public Group createGroup(String name, String uId, String token){ return null; } public Group getGroupByGId(String gId, String token){ return null; } public Respo deleteGroup(String gId, String token){ return null; } }