A gist that allows to check whether or not objects given through a Bundle are of the same instance. Used for an example on http://magicmicky.github.io/android_development/loose_coupling_using_otto/

BundleTestActivity.java

package com.magicmicky.loosecoopling;

import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


public class MyActivity extends ActionBarActivity {
    private final static String TAG="Activity";
    private static final String ARG_SHOP = "shop";
    private static final String ARG_FRG = "frg";
    private Shop mShop;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);
        if (savedInstanceState == null) {
            this.mShop = new Shop("Test shop");
            Log.d(TAG, "shop created: " + ((Object)mShop).toString());
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, BlankFragment.newInstance(mShop))
                    .commit();
        } else {
            this.mShop = (Shop) savedInstanceState.get(ARG_SHOP);
            Log.d(TAG, "shop retrieved from instance state: " + ((Object) mShop).toString());
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        Log.i(TAG, "Saving shop: " + ((Object) mShop).toString());
        outState.putParcelable(ARG_SHOP, mShop);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.v(TAG, "onDestroy()");
    }
    
    /*
     * Fragment
     */
    public static class BlankFragment extends Fragment {
        private static final String ARG_SHOP = "shop";
        private static final String TAG = "Fragment";
        private Shop mShop;

        public static BlankFragment newInstance(Shop s) {
            BlankFragment fragment = new BlankFragment();
            Bundle args = new Bundle();
            args.putParcelable(ARG_SHOP, s);
            fragment.setArguments(args);
            return fragment;
        }
        public BlankFragment() {
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            if (getArguments() != null) {
                this.mShop = (Shop) getArguments().get(ARG_SHOP);
                Log.d(TAG, "shop given to fragment: " + ((Object) mShop).toString());

            }
            if(savedInstanceState!=null && savedInstanceState.containsKey(ARG_SHOP)) {
                this.mShop = (Shop) savedInstanceState.get(ARG_SHOP);
                Log.d(TAG, "shop retrieved from instance state: " + ((Object) mShop).toString());
            }
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            Log.v(TAG, "onDestroy()");
        }

        @Override
        public void onSaveInstanceState(Bundle outState) {
            super.onSaveInstanceState(outState);
            Log.i(TAG, "Saving shop: " + ((Object) mShop).toString());
            outState.putParcelable(ARG_SHOP, mShop);
        }
    }
    
    /*
     * Model
     */
    public static class Shop implements Parcelable {
        private final static String TAG="Shop";
        private String name;

        public Shop(String name) {
            this.name = name;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }


        @Override
        public int describeContents() {
            return 0;
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            dest.writeString(this.name);
            Log.v(TAG, "writeToParcel of " + ((Object)this).toString());
        }

        private Shop(Parcel in) {
            this.name = in.readString();
            Log.v(TAG, "Creating from parcel of " + ((Object)this).toString());

        }

        public static final Creator<Shop> CREATOR = new Creator<Shop>() {
            public Shop createFromParcel(Parcel source) {
                return new Shop(source);
            }

            public Shop[] newArray(int size) {
                return new Shop[size];
            }
        };
    }
}