public JSONObject listFollowers(String email, Integer limit,String order,Integer since_id) {
        JSONObject result = new JSONObject();
        JSONArray response = new JSONArray();
        try {
            StringBuilder querry = new StringBuilder("SELECT id, username, about, name, email, isAnonymous FROM followers JOIN users ON email = follower WHERE followee = ? ");
            if(since_id != null) { querry.append("and id >= ? "); }
            if(order != null && order.equals("asc")) { querry.append("order by name asc "); }
            else { querry.append("order by name desc "); }
            if(limit != null) { querry.append("limit ? "); }

            PreparedStatement stmt = con.prepareStatement(querry.toString());

            Integer arg = 1;
            stmt.setString(arg,email);
            ++arg;
            if(since_id != null) {
                stmt.setInt(arg,since_id);
                ++arg;
            }

            if(limit != null) {
                stmt.setInt(arg,limit);
                ++arg;
            }

            ResultSet user = stmt.executeQuery();

            while (user.next()) {
                JSONObject jsonObject = new JSONObject();

                jsonObject.put("id", user.getInt("id"));

                jsonObject.put("username",user.getString("username"));
                jsonObject.put("about", user.getString("about"));
                jsonObject.put("name", user.getString("name"));
                jsonObject.put("email", user.getString("email"));
                jsonObject.put("isAnonymous", user.getBoolean("isAnonymous"));
                jsonObject.put("followers", getListFollowers(user.getString("email"), con));
                jsonObject.put("following", getListFollowings(user.getString("email"), con));
                jsonObject.put("subscriptions", getListSubscriptions(user.getString("email"),con));

                response.put(jsonObject);
            }
            result.put("code", 0);
            result.put("response", response);
        } catch (SQLException | JSONException e) { e.printStackTrace(); }
        return result;
    }