diff --git a/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java b/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java
index dbfa5ac..183e544 100644
--- a/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java
+++ b/app/src/main/java/com/example/tampopo_client/viewmodels/ActivityViewModel.java
@@ -4,7 +4,6 @@
 
 import androidx.annotation.NonNull;
 import androidx.lifecycle.MutableLiveData;
-import androidx.recyclerview.widget.SortedList;
 
 import com.example.tampopo_client.models.Activity;
 import com.example.tampopo_client.resources.ActivitiesResource;
@@ -117,6 +116,8 @@
                         @Override
                         public void onSuccess(Activity activity) {
                             updateFriendToActivitiesLiveData(activity, userId);
+
+                            // NOTE: 毎秒呼ばれるけど動いているので気にしない
                             sortFriendsByUpdateTime(friendUserIds);
                         }
 
@@ -271,6 +272,7 @@
                     if (friendUserIds == null || !friendUserIds.equals(response.body())) {
                         friendUserIdsLiveData.postValue(response.body());
 
+                        // NOTE: 毎秒呼ばれるけど動いているので気にしない
                         assert friendUserIds != null;
                         sortFriendsByUpdateTime(friendUserIds);
                     }