title: how can remove push value from firebase
body: <p>I want to remove the push value generated from firebase.Can I able to do that and how?</p>
  
  <p><a href="https://i.stack.imgur.com/36Ng7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/36Ng7.png" alt="enter image description here"></a></p>
  
  <p>When user follow someone, I write some code to generate push value to firebase for notification. The problem is I didn't written code for removing the value when user unfollow and follows the user again and again it shows lots of notification ..like pic down below</p>
  
  <pre><code>    HashMap&lt;String ,String&gt; notificationData = new HashMap&lt;&gt;();
              notificationData.put("from",FirebaseAuth.getInstance().getCurrentUser().getUid());
              notificationData.put("type","following");
              mNotification.child(mUser.getUser_id()).push().setValue(notificationData).addOnSuccessListener(new OnSuccessListener&lt;Void&gt;() {
                  @Override
                  public void onSuccess(Void aVoid) {
                      setFollowing();
                  }
              }).addOnFailureListener(new OnFailureListener() {
                  @Override
                  public void onFailure(@NonNull Exception e) {
  
                  }
              });
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/nia4f.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nia4f.png" alt="enter image description here"></a></p>