title: cant call publishProgress from inside a onDataChange()
body: <pre><code>DatabaseReference myRef = database.getReference(address[0]+"/"+address[1]);
                  myRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
               // This method is called once with the initial value and again
               // whenever data at this location is updated.
               String value = dataSnapshot.getValue(String.class);
                          publishProgress(getping(value));
         }
  </code></pre>
  
  <p>publishProgress always gets skipped.</p>