Address review comments at aosp/3249945

This change includes:
  1. Rename binder interfaces.
  2. Use a dedicated class to pass the result of
     get{Total|Iface|Uid}Stats, as it is 25% faster than passing
     a NetworkStats object through the binder interface.
  3. Remove the binder interface only used by the test.
  4. Remove NetworkStatsBinderTest on R and S, since the binder
     interface is removed, the mainlined service does not run on
     those versions and the chance of breaking these tests on
     R and S is low.
  5. Remove useless TODO comments.

Test: atest FrameworksNetTests:android.net.connectivity.com.android.server.net.NetworkStatsServiceTest \
      CtsNetTestCases:android.net.cts.NetworkStatsBinderTest \
      FrameworksNetIntegrationTests:com.android.server.net.integrationtests.NetworkStatsIntegrationTest
Bug: 372851500
Bug: 343260158

Change-Id: Ibd79a17218f54f0117d8ef5d7b9ec6073356f923
diff --git a/framework-t/src/android/net/INetworkStatsService.aidl b/framework-t/src/android/net/INetworkStatsService.aidl
index 01ac106..ce57a4a 100644
--- a/framework-t/src/android/net/INetworkStatsService.aidl
+++ b/framework-t/src/android/net/INetworkStatsService.aidl
@@ -21,10 +21,10 @@
 import android.net.Network;
 import android.net.NetworkStateSnapshot;
 import android.net.NetworkStats;
-import android.net.NetworkStatsHistory;
 import android.net.NetworkTemplate;
 import android.net.UnderlyingNetworkInfo;
 import android.net.netstats.IUsageCallback;
+import android.net.netstats.StatsResult;
 import android.net.netstats.provider.INetworkStatsProvider;
 import android.net.netstats.provider.INetworkStatsProviderCallback;
 import android.os.IBinder;
@@ -78,16 +78,13 @@
     void unregisterUsageRequest(in DataUsageRequest request);
 
     /** Get the uid stats information since boot */
-    NetworkStats getTypelessUidStats(int uid);
+    StatsResult getUidStats(int uid);
 
     /** Get the iface stats information since boot */
-    NetworkStats getTypelessIfaceStats(String iface);
+    StatsResult getIfaceStats(String iface);
 
     /** Get the total network stats information since boot */
-    NetworkStats getTypelessTotalStats();
-
-    /** Get the uid stats information (with specified type) since boot */
-    long getUidStats(int uid, int type);
+    StatsResult getTotalStats();
 
     /** Registers a network stats provider */
     INetworkStatsProviderCallback registerNetworkStatsProvider(String tag,
diff --git a/framework-t/src/android/net/TrafficStats.java b/framework-t/src/android/net/TrafficStats.java
index 3b6a69b..ab0aaa0 100644
--- a/framework-t/src/android/net/TrafficStats.java
+++ b/framework-t/src/android/net/TrafficStats.java
@@ -19,6 +19,7 @@
 import static android.annotation.SystemApi.Client.MODULE_LIBRARIES;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.RequiresPermission;
 import android.annotation.SuppressLint;
 import android.annotation.SystemApi;
@@ -29,6 +30,7 @@
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
 import android.media.MediaPlayer;
+import android.net.netstats.StatsResult;
 import android.os.Binder;
 import android.os.Build;
 import android.os.RemoteException;
@@ -40,8 +42,6 @@
 import java.net.DatagramSocket;
 import java.net.Socket;
 import java.net.SocketException;
-import java.util.Iterator;
-import java.util.Objects;
 
 
 /**
@@ -963,13 +963,13 @@
                 || android.os.Process.myUid() != uid) {
             return UNSUPPORTED;
         }
-        final NetworkStats stats;
+        final StatsResult stats;
         try {
-            stats = getStatsService().getTypelessUidStats(uid);
+            stats = getStatsService().getUidStats(uid);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
-        return getValueForTypeFromFirstEntry(stats, type);
+        return getEntryValueForType(stats, type);
     }
 
     /** @hide */
@@ -977,13 +977,13 @@
         if (!isEntryValueTypeValid(type)) {
             return UNSUPPORTED;
         }
-        final NetworkStats stats;
+        final StatsResult stats;
         try {
-            stats = getStatsService().getTypelessTotalStats();
+            stats = getStatsService().getTotalStats();
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
-        return getValueForTypeFromFirstEntry(stats, type);
+        return getEntryValueForType(stats, type);
     }
 
     /** @hide */
@@ -991,13 +991,13 @@
         if (!isEntryValueTypeValid(type)) {
             return UNSUPPORTED;
         }
-        final NetworkStats stats;
+        final StatsResult stats;
         try {
-            stats = getStatsService().getTypelessIfaceStats(iface);
+            stats = getStatsService().getIfaceStats(iface);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
-        return getValueForTypeFromFirstEntry(stats, type);
+        return getEntryValueForType(stats, type);
     }
 
     /**
@@ -1127,18 +1127,18 @@
     public static final int TYPE_TX_PACKETS = 3;
 
     /** @hide */
-    private static long getEntryValueForType(@NonNull NetworkStats.Entry entry, int type) {
-        Objects.requireNonNull(entry);
+    private static long getEntryValueForType(@Nullable StatsResult stats, int type) {
+        if (stats == null) return UNSUPPORTED;
         if (!isEntryValueTypeValid(type)) return UNSUPPORTED;
         switch (type) {
             case TYPE_RX_BYTES:
-                return entry.getRxBytes();
+                return stats.rxBytes;
             case TYPE_RX_PACKETS:
-                return entry.getRxPackets();
+                return stats.rxPackets;
             case TYPE_TX_BYTES:
-                return entry.getTxBytes();
+                return stats.txBytes;
             case TYPE_TX_PACKETS:
-                return entry.getTxPackets();
+                return stats.txPackets;
             default:
                 throw new IllegalStateException("Bug: Invalid type: "
                         + type + " should not reach here.");
@@ -1157,13 +1157,5 @@
                 return false;
         }
     }
-
-    /** @hide */
-    public static long getValueForTypeFromFirstEntry(@NonNull NetworkStats stats, int type) {
-        Objects.requireNonNull(stats);
-        Iterator<NetworkStats.Entry> iter = stats.iterator();
-        if (!iter.hasNext()) return UNSUPPORTED;
-        return getEntryValueForType(iter.next(), type);
-    }
 }
 
diff --git a/framework-t/src/android/net/netstats/StatsResult.aidl b/framework-t/src/android/net/netstats/StatsResult.aidl
new file mode 100644
index 0000000..3f09566
--- /dev/null
+++ b/framework-t/src/android/net/netstats/StatsResult.aidl
@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) 2024, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net.netstats;
+
+/**
+ * A lightweight class to pass result of TrafficStats#get{Total|Iface|Uid}Stats.
+ *
+ * @hide
+ */
+@JavaDerive(equals=true, toString=true)
+@JavaOnlyImmutable
+parcelable StatsResult {
+    long rxBytes;
+    long rxPackets;
+    long txBytes;
+    long txPackets;
+}
\ No newline at end of file
diff --git a/service-t/src/com/android/server/net/NetworkStatsService.java b/service-t/src/com/android/server/net/NetworkStatsService.java
index 294a85a..7572f0e 100644
--- a/service-t/src/com/android/server/net/NetworkStatsService.java
+++ b/service-t/src/com/android/server/net/NetworkStatsService.java
@@ -52,7 +52,6 @@
 import static android.net.TrafficStats.KB_IN_BYTES;
 import static android.net.TrafficStats.MB_IN_BYTES;
 import static android.net.TrafficStats.UID_TETHERING;
-import static android.net.TrafficStats.getValueForTypeFromFirstEntry;
 import static android.net.connectivity.ConnectivityCompatChanges.ENABLE_TRAFFICSTATS_RATE_LIMIT_CACHE;
 import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_UID;
 import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_UID_TAG;
@@ -127,6 +126,7 @@
 import android.net.Uri;
 import android.net.netstats.IUsageCallback;
 import android.net.netstats.NetworkStatsDataMigrationUtils;
+import android.net.netstats.StatsResult;
 import android.net.netstats.provider.INetworkStatsProvider;
 import android.net.netstats.provider.INetworkStatsProviderCallback;
 import android.net.netstats.provider.NetworkStatsProvider;
@@ -2133,18 +2133,12 @@
         }
     }
 
+    @Nullable
     @Override
-    public long getUidStats(int uid, int type) {
-        return getValueForTypeFromFirstEntry(getTypelessUidStats(uid), type);
-    }
-
-    @NonNull
-    @Override
-    public NetworkStats getTypelessUidStats(int uid) {
-        final NetworkStats stats = new NetworkStats(0, 0);
+    public StatsResult getUidStats(int uid) {
         final int callingUid = Binder.getCallingUid();
         if (callingUid != android.os.Process.SYSTEM_UID && callingUid != uid) {
-            return stats;
+            return null;
         }
         final NetworkStats.Entry entry;
         if (mAlwaysUseTrafficStatsServiceRateLimitCache
@@ -2153,10 +2147,7 @@
                     () -> mDeps.nativeGetUidStat(uid));
         } else entry = mDeps.nativeGetUidStat(uid);
 
-        if (entry != null) {
-            stats.insertEntry(entry);
-        }
-        return stats;
+        return getStatsResultFromEntryOrNull(entry);
     }
 
     @Nullable
@@ -2173,9 +2164,9 @@
         return entry;
     }
 
-    @NonNull
+    @Nullable
     @Override
-    public NetworkStats getTypelessIfaceStats(@NonNull String iface) {
+    public StatsResult getIfaceStats(@NonNull String iface) {
         Objects.requireNonNull(iface);
 
         final NetworkStats.Entry entry;
@@ -2186,11 +2177,13 @@
                     () -> getIfaceStatsInternal(iface));
         } else entry = getIfaceStatsInternal(iface);
 
-        NetworkStats stats = new NetworkStats(0, 0);
-        if (entry != null) {
-            stats.insertEntry(entry);
-        }
-        return stats;
+        return getStatsResultFromEntryOrNull(entry);
+    }
+
+    @Nullable
+    private StatsResult getStatsResultFromEntryOrNull(@Nullable NetworkStats.Entry entry) {
+        if (entry == null) return null;
+        return new StatsResult(entry.rxBytes, entry.rxPackets, entry.txBytes, entry.txPackets);
     }
 
     @Nullable
@@ -2203,9 +2196,9 @@
         return entry;
     }
 
-    @NonNull
+    @Nullable
     @Override
-    public NetworkStats getTypelessTotalStats() {
+    public StatsResult getTotalStats() {
         final NetworkStats.Entry entry;
         if (mAlwaysUseTrafficStatsServiceRateLimitCache
                 || mDeps.isChangeEnabled(
@@ -2214,11 +2207,7 @@
                     IFACE_ALL, UID_ALL, () -> getTotalStatsInternal());
         } else entry = getTotalStatsInternal();
 
-        final NetworkStats stats = new NetworkStats(0, 0);
-        if (entry != null) {
-            stats.insertEntry(entry);
-        }
-        return stats;
+        return getStatsResultFromEntryOrNull(entry);
     }
 
     @Override
diff --git a/tests/cts/net/src/android/net/cts/NetworkStatsBinderTest.java b/tests/cts/net/src/android/net/cts/NetworkStatsBinderTest.java
index 1a48983..10adee0 100644
--- a/tests/cts/net/src/android/net/cts/NetworkStatsBinderTest.java
+++ b/tests/cts/net/src/android/net/cts/NetworkStatsBinderTest.java
@@ -19,28 +19,28 @@
 import static android.os.Process.INVALID_UID;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.content.Context;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.net.INetworkStatsService;
 import android.net.TrafficStats;
+import android.net.connectivity.android.net.netstats.StatsResult;
 import android.os.Build;
 import android.os.IBinder;
 import android.os.Process;
 import android.os.RemoteException;
-import android.test.AndroidTestCase;
-import android.util.SparseArray;
 
 import androidx.test.InstrumentationRegistry;
-import androidx.test.runner.AndroidJUnit4;
 
 import com.android.internal.util.CollectionUtils;
+import com.android.testutils.ConnectivityModuleTest;
 import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
 
-import org.junit.Before;
-import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -48,37 +48,20 @@
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.function.Function;
 import java.util.function.Predicate;
 
-@RunWith(AndroidJUnit4.class)
+@ConnectivityModuleTest
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2) // Mainline NetworkStats starts from T.
+@RunWith(DevSdkIgnoreRunner.class)
 public class NetworkStatsBinderTest {
-    // NOTE: These are shamelessly copied from TrafficStats.
-    private static final int TYPE_RX_BYTES = 0;
-    private static final int TYPE_RX_PACKETS = 1;
-    private static final int TYPE_TX_BYTES = 2;
-    private static final int TYPE_TX_PACKETS = 3;
-
-    @Rule
-    public DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule(
-            Build.VERSION_CODES.Q /* ignoreClassUpTo */);
-
-    private final SparseArray<Function<Integer, Long>> mUidStatsQueryOpArray = new SparseArray<>();
-
-    @Before
-    public void setUp() throws Exception {
-        mUidStatsQueryOpArray.put(TYPE_RX_BYTES, uid -> TrafficStats.getUidRxBytes(uid));
-        mUidStatsQueryOpArray.put(TYPE_RX_PACKETS, uid -> TrafficStats.getUidRxPackets(uid));
-        mUidStatsQueryOpArray.put(TYPE_TX_BYTES, uid -> TrafficStats.getUidTxBytes(uid));
-        mUidStatsQueryOpArray.put(TYPE_TX_PACKETS, uid -> TrafficStats.getUidTxPackets(uid));
-    }
-
-    private long getUidStatsFromBinder(int uid, int type) throws Exception {
-        Method getServiceMethod = Class.forName("android.os.ServiceManager")
+    @Nullable
+    private StatsResult getUidStatsFromBinder(int uid) throws Exception {
+        final Method getServiceMethod = Class.forName("android.os.ServiceManager")
                 .getDeclaredMethod("getService", new Class[]{String.class});
-        IBinder binder = (IBinder) getServiceMethod.invoke(null, Context.NETWORK_STATS_SERVICE);
-        INetworkStatsService nss = INetworkStatsService.Stub.asInterface(binder);
-        return nss.getUidStats(uid, type);
+        final IBinder binder = (IBinder) getServiceMethod.invoke(
+                null, Context.NETWORK_STATS_SERVICE);
+        final INetworkStatsService nss = INetworkStatsService.Stub.asInterface(binder);
+        return nss.getUidStats(uid);
     }
 
     private int getFirstAppUidThat(@NonNull Predicate<Integer> predicate) {
@@ -108,38 +91,34 @@
         if (notMyUid != INVALID_UID) testUidList.add(notMyUid);
 
         for (final int uid : testUidList) {
-            for (int i = 0; i < mUidStatsQueryOpArray.size(); i++) {
-                final int type = mUidStatsQueryOpArray.keyAt(i);
-                try {
-                    final long uidStatsFromBinder = getUidStatsFromBinder(uid, type);
-                    final long uidTrafficStats = mUidStatsQueryOpArray.get(type).apply(uid);
+            try {
+                final StatsResult uidStatsFromBinder = getUidStatsFromBinder(uid);
 
-                    // Verify that UNSUPPORTED is returned if the uid is not current app uid.
-                    if (uid != myUid) {
-                        assertEquals(uidStatsFromBinder, TrafficStats.UNSUPPORTED);
-                    }
+                if (uid != myUid) {
+                    // Verify that null is returned if the uid is not current app uid.
+                    assertNull(uidStatsFromBinder);
+                } else {
                     // Verify that returned result is the same with the result get from
                     // TrafficStats.
-                    // TODO: If the test is flaky then it should instead assert that the values
-                    //  are approximately similar.
-                    assertEquals("uidStats is not matched for query type " + type
-                                    + ", uid=" + uid + ", myUid=" + myUid, uidTrafficStats,
-                            uidStatsFromBinder);
-                } catch (IllegalAccessException e) {
-                    /* Java language access prevents exploitation. */
-                    return;
-                } catch (InvocationTargetException e) {
-                    /* Underlying method has been changed. */
-                    return;
-                } catch (ClassNotFoundException e) {
-                    /* not vulnerable if hidden API no longer available */
-                    return;
-                } catch (NoSuchMethodException e) {
-                    /* not vulnerable if hidden API no longer available */
-                    return;
-                } catch (RemoteException e) {
-                    return;
+                    assertEquals(uidStatsFromBinder.rxBytes, TrafficStats.getUidRxBytes(uid));
+                    assertEquals(uidStatsFromBinder.rxPackets, TrafficStats.getUidRxPackets(uid));
+                    assertEquals(uidStatsFromBinder.txBytes, TrafficStats.getUidTxBytes(uid));
+                    assertEquals(uidStatsFromBinder.txPackets, TrafficStats.getUidTxPackets(uid));
                 }
+            } catch (IllegalAccessException e) {
+                /* Java language access prevents exploitation. */
+                return;
+            } catch (InvocationTargetException e) {
+                /* Underlying method has been changed. */
+                return;
+            } catch (ClassNotFoundException e) {
+                /* not vulnerable if hidden API no longer available */
+                return;
+            } catch (NoSuchMethodException e) {
+                /* not vulnerable if hidden API no longer available */
+                return;
+            } catch (RemoteException e) {
+                return;
             }
         }
     }
diff --git a/tests/unit/java/android/net/TrafficStatsTest.kt b/tests/unit/java/android/net/TrafficStatsTest.kt
deleted file mode 100644
index c61541e..0000000
--- a/tests/unit/java/android/net/TrafficStatsTest.kt
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
-* Copyright (C) 2024 The Android Open Source Project
-*
-* Licensed under the Apache License, Version 2.0 (the "License");
-* you may not use this file except in compliance with the License.
-* You may obtain a copy of the License at
-*
-*      http://www.apache.org/licenses/LICENSE-2.0
-*
-* Unless required by applicable law or agreed to in writing, software
-* distributed under the License is distributed on an "AS IS" BASIS,
-* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-* See the License for the specific language governing permissions and
-* limitations under the License.
-*/
-
-package android.net
-
-import android.net.TrafficStats.getValueForTypeFromFirstEntry
-import android.net.TrafficStats.TYPE_RX_BYTES
-import android.net.TrafficStats.UNSUPPORTED
-import android.os.Build
-import com.android.testutils.DevSdkIgnoreRule
-import com.android.testutils.DevSdkIgnoreRunner
-import org.junit.Test
-import org.junit.runner.RunWith
-import kotlin.test.assertEquals
-
-private const val TEST_IFACE1 = "test_iface1"
-
-@RunWith(DevSdkIgnoreRunner::class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.TIRAMISU)
-class TrafficStatsTest {
-
-    @Test
-    fun testGetValueForTypeFromFirstEntry() {
-        var stats: NetworkStats = NetworkStats(0, 0)
-        // empty stats
-        assertEquals(getValueForTypeFromFirstEntry(stats, TYPE_RX_BYTES), UNSUPPORTED.toLong())
-        // invalid type
-        stats.insertEntry(TEST_IFACE1, 1, 2, 3, 4)
-        assertEquals(getValueForTypeFromFirstEntry(stats, 1000), UNSUPPORTED.toLong())
-        // valid type
-        assertEquals(getValueForTypeFromFirstEntry(stats, TYPE_RX_BYTES), 1)
-    }
-}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
index ef4c44d..e6f8d21 100644
--- a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -56,7 +56,6 @@
 import static android.net.TrafficStats.MB_IN_BYTES;
 import static android.net.TrafficStats.UID_REMOVED;
 import static android.net.TrafficStats.UID_TETHERING;
-import static android.net.TrafficStats.getValueForTypeFromFirstEntry;
 import static android.net.connectivity.ConnectivityCompatChanges.ENABLE_TRAFFICSTATS_RATE_LIMIT_CACHE;
 import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_UID;
 import static android.net.netstats.NetworkStatsDataMigrationUtils.PREFIX_UID_TAG;
@@ -128,8 +127,8 @@
 import android.net.TestNetworkSpecifier;
 import android.net.TetherStatsParcel;
 import android.net.TetheringManager;
-import android.net.TrafficStats;
 import android.net.UnderlyingNetworkInfo;
+import android.net.netstats.StatsResult;
 import android.net.netstats.provider.INetworkStatsProviderCallback;
 import android.net.wifi.WifiInfo;
 import android.os.DropBoxManager;
@@ -209,7 +208,6 @@
 import java.util.Set;
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.function.Function;
 
 /**
  * Tests for {@link NetworkStatsService}.
@@ -2515,22 +2513,18 @@
     // Assert for 3 different API return values respectively.
     private void assertTrafficStatsValues(String iface, int uid, long rxBytes, long rxPackets,
             long txBytes, long txPackets) {
-        assertTrafficStatsValuesThat(rxBytes, rxPackets, txBytes, txPackets,
-                (type) -> getValueForTypeFromFirstEntry(mService.getTypelessTotalStats(), type));
-        assertTrafficStatsValuesThat(rxBytes, rxPackets, txBytes, txPackets,
-                (type) -> getValueForTypeFromFirstEntry(
-                        mService.getTypelessIfaceStats(iface), type)
-        );
-        assertTrafficStatsValuesThat(rxBytes, rxPackets, txBytes, txPackets,
-                (type) -> getValueForTypeFromFirstEntry(mService.getTypelessUidStats(uid), type));
+        assertStatsResultEquals(mService.getTotalStats(), rxBytes, rxPackets, txBytes, txPackets);
+        assertStatsResultEquals(mService.getIfaceStats(iface), rxBytes, rxPackets, txBytes,
+                txPackets);
+        assertStatsResultEquals(mService.getUidStats(uid), rxBytes, rxPackets, txBytes, txPackets);
     }
 
-    private void assertTrafficStatsValuesThat(long rxBytes, long rxPackets, long txBytes,
-            long txPackets, Function<Integer, Long> fetcher) {
-        assertEquals(rxBytes, (long) fetcher.apply(TrafficStats.TYPE_RX_BYTES));
-        assertEquals(rxPackets, (long) fetcher.apply(TrafficStats.TYPE_RX_PACKETS));
-        assertEquals(txBytes, (long) fetcher.apply(TrafficStats.TYPE_TX_BYTES));
-        assertEquals(txPackets, (long) fetcher.apply(TrafficStats.TYPE_TX_PACKETS));
+    private void assertStatsResultEquals(StatsResult stats, long rxBytes, long rxPackets,
+            long txBytes, long txPackets) {
+        assertEquals(rxBytes, stats.rxBytes);
+        assertEquals(rxPackets, stats.rxPackets);
+        assertEquals(txBytes, stats.txBytes);
+        assertEquals(txPackets, stats.txPackets);
     }
 
     private void assertShouldRunComparison(boolean expected, boolean isDebuggable) {