I am sending data in hashmap back to parent activity from child acitvity

here is my code
Child activity

```
    private void sendDataToPrevPg(HashMap<String, String> hm) {     
    // Send to previous activity page
    Bundle bndle = new Bundle();
    bndle.putSerializable("stockList", (Serializable) hm);

    Intent intent = new Intent();
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intent.putExtra("stkList",bndle);
    setResult(RESULT_OK, intent);           
    this.finish();      
}

```

In parent

```
@SuppressWarnings("unchecked")
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (resultCode == RESULT_OK ) {         
        if (data.hasExtra("stkList")) {             

            Bundle wrapper = getIntent().getBundleExtra("stkList");
            HashMap<String, String> myClass3 = (HashMap<String, String>) wrapper.getSerializable("stkList");
            System.out.println("...serialized data4.."+myClass3);
        }
    }
}

```

showing error at line 

```
 HashMap<String, String> myClass3 = (HashMap<String, String>)       wrapper.getSerializable("stkList");

```

Logcat::
Caused by: java.lang.NullPointerException

how to send data in hashmap? to parent activity