diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Event.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Event.java
index 69277a1..0b50dfd 100644
--- a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Event.java
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/Event.java
@@ -22,6 +22,8 @@
 
 import com.android.server.nearby.intdefs.NearbyEventIntDefs.EventCode;
 
+import java.util.Objects;
+
 import javax.annotation.Nullable;
 
 /**
@@ -31,15 +33,15 @@
 public class Event implements Parcelable {
 
     private final @EventCode int mEventCode;
-    private final long mTimeStamp;
+    private final long mTimestamp;
     private final Short mProfile;
     private final BluetoothDevice mBluetoothDevice;
     private final Exception mException;
 
-    private Event(@EventCode int eventCode, long timeStamp, Short profile,
-            BluetoothDevice bluetoothDevice, Exception exception) {
+    private Event(@EventCode int eventCode, long timestamp, @Nullable Short profile,
+            @Nullable BluetoothDevice bluetoothDevice, @Nullable Exception exception) {
         mEventCode = eventCode;
-        mTimeStamp = timeStamp;
+        mTimestamp = timestamp;
         mProfile = profile;
         mBluetoothDevice = bluetoothDevice;
         mException = exception;
@@ -56,7 +58,7 @@
      * Returns timestamp.
      */
     public long getTimestamp() {
-        return mTimeStamp;
+        return mTimestamp;
     }
 
     /**
@@ -111,12 +113,50 @@
         return getException() != null;
     }
 
+    @Override
+    public String toString() {
+        return "Event{"
+                + "eventCode=" + mEventCode + ", "
+                + "timestamp=" + mTimestamp + ", "
+                + "profile=" + mProfile + ", "
+                + "bluetoothDevice=" + mBluetoothDevice + ", "
+                + "exception=" + mException
+                + "}";
+    }
+
+    @Override
+    public boolean equals(@Nullable Object o) {
+        if (o == this) {
+            return true;
+        }
+        if (o instanceof Event) {
+            Event that = (Event) o;
+            return this.mEventCode == that.getEventCode()
+                    && this.mTimestamp == that.getTimestamp()
+                    && (this.mProfile == null
+                        ? that.getProfile() == null : this.mProfile.equals(that.getProfile()))
+                    && (this.mBluetoothDevice == null
+                        ? that.getBluetoothDevice() == null :
+                            this.mBluetoothDevice.equals(that.getBluetoothDevice()))
+                    && (this.mException == null
+                        ?  that.getException() == null :
+                            this.mException.equals(that.getException()));
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mEventCode, mTimestamp, mProfile, mBluetoothDevice, mException);
+    }
+
+
     /**
      * Builder
      */
     public static class Builder {
         private @EventCode int mEventCode;
-        private long mTimeStamp;
+        private long mTimestamp;
         private Short mProfile;
         private BluetoothDevice mBluetoothDevice;
         private Exception mException;
@@ -133,7 +173,7 @@
          * Set timestamp.
          */
         public Builder setTimestamp(long timestamp) {
-            this.mTimeStamp = timestamp;
+            this.mTimestamp = timestamp;
             return this;
         }
 
@@ -165,7 +205,7 @@
          * Builds event.
          */
         public Event build() {
-            return new Event(mEventCode, mTimeStamp, mProfile, mBluetoothDevice, mException);
+            return new Event(mEventCode, mTimestamp, mProfile, mBluetoothDevice, mException);
         }
     }
 
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/FastPairConnection.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/FastPairConnection.java
index b1e1412..a7c05d6 100644
--- a/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/FastPairConnection.java
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/fastpair/FastPairConnection.java
@@ -27,7 +27,9 @@
 import com.android.server.nearby.common.bluetooth.BluetoothException;
 
 import java.security.GeneralSecurityException;
+import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeoutException;
 
@@ -176,6 +178,32 @@
         public String getAddress() {
             return mAddress;
         }
+
+        @Override
+        public String toString() {
+            return "SharedSecret{"
+                    + "key=" + Arrays.toString(mKey) + ", "
+                    + "address=" + mAddress
+                    + "}";
+        }
+
+        @Override
+        public boolean equals(@Nullable Object o) {
+            if (o == this) {
+                return true;
+            }
+            if (o instanceof SharedSecret) {
+                SharedSecret that = (SharedSecret) o;
+                return Arrays.equals(this.mKey, that.getKey())
+                        && this.mAddress.equals(that.getAddress());
+            }
+            return false;
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(Arrays.hashCode(mKey), mAddress);
+        }
     }
 
     /** Invokes if gotten the passkey. */
diff --git a/nearby/service/java/com/android/server/nearby/common/bluetooth/gatt/BluetoothGattHelper.java b/nearby/service/java/com/android/server/nearby/common/bluetooth/gatt/BluetoothGattHelper.java
index 170afd1..f17094d 100644
--- a/nearby/service/java/com/android/server/nearby/common/bluetooth/gatt/BluetoothGattHelper.java
+++ b/nearby/service/java/com/android/server/nearby/common/bluetooth/gatt/BluetoothGattHelper.java
@@ -576,22 +576,28 @@
         }
 
         @Override
+        public String toString() {
+            return "ConnectionOptions{"
+                    + "autoConnect=" + mAutoConnect + ", "
+                    + "connectionTimeoutMillis=" + mConnectionTimeoutMillis + ", "
+                    + "connectionPriority=" + mConnectionPriority + ", "
+                    + "mtu=" + mMtu
+                    + "}";
+        }
+
+        @Override
         public boolean equals(Object o) {
             if (this == o) {
                 return true;
             }
-            if (o == null) {
-                return false;
+            if (o instanceof ConnectionOptions) {
+                ConnectionOptions that = (ConnectionOptions) o;
+                return this.mAutoConnect == that.autoConnect()
+                        && this.mConnectionTimeoutMillis == that.connectionTimeoutMillis()
+                        && this.mConnectionPriority.equals(that.connectionPriority())
+                        && this.mMtu.equals(that.mtu());
             }
-            if (!(o instanceof ConnectionOptions)) {
-                return false;
-            }
-            ConnectionOptions oc = (ConnectionOptions) o;
-
-            return (this.autoConnect() == oc.autoConnect()
-                    && this.connectionTimeoutMillis() == oc.connectionTimeoutMillis()
-                    && this.connectionPriority().equals(oc.connectionPriority())
-                    && this.mtu().equals(oc.mtu()));
+            return false;
         }
 
         @Override