title: recycler view shows redundant data after updating the list
body: <p>I am trying to create a news application. I have prepared an Adapter, recycler view, and a JSON parsing algorithm. When we reached at end of the recycler view parsing algorithm makes another request to get next items for recycler view to show. Everything is fine till here
  but when i set to adapter it shows redundant data.</p>
  <p>I don't understand what is going on. I have been trying so hard but no results please help me. <br><br>
  When recycler view reaches at the end this method got invoked.</p>
  <pre><code> public void loadMore(String url){
  
      List&lt;NewsEntity&gt; list1 = new ArrayList&lt;&gt;();
  
      Log.d(TAG, &quot;parseJson: Inside parser&quot;);
      JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null,
              new Response.Listener&lt;JSONObject&gt;() {
                  @Override
                  public void onResponse(JSONObject response) {
  
                      try {
                          JSONArray jsonArray = response.getJSONArray(&quot;results&quot;);
  
                          for (int i = 0; i &lt; jsonArray.length(); i++) {
                              JSONObject results = jsonArray.getJSONObject(i);
                              String description = results.getString(&quot;description&quot;);
                              String url1 = results.getString(&quot;image_url&quot;);
                              String title = results.getString(&quot;title&quot;);
                              String date = results.getString(&quot;pubDate&quot;);
                              String author = results.getString(&quot;creator&quot;);
                              String content = results.getString(&quot;content&quot;);
                              String source = results.getString(&quot;source_id&quot;);
                              String link = results.getString(&quot;link&quot;);
                              Log.d(TAG, &quot;onResponse: Parsing alright&quot;);
  
                                  if (content.length() &gt;= description.length()) {
                                      NewsEntity entity = new NewsEntity(title, content, url1, date, author, source,link,false);
                                      list1.add(entity);
                                  } else {
                                      NewsEntity entity = new NewsEntity(title, description, url1, date, author, source,link,false);
                                      list1.add(entity);
                                  }
  
  
                          }
                          adapter.setList(list1);
                          isLoading = false;
                          progressBar.setVisibility(View.GONE);
  
                      }catch (Exception e){
                          e.printStackTrace();
                      }
  } },new Response.ErrorListener() {
                      @Override
                      public void onErrorResponse(VolleyError error) {
                          error.printStackTrace();
                      }
      });
      requestQueue.add(request);
  }
  </code></pre>
  <p>Adpater set List</p>
  <pre><code> public void setList(List&lt;NewsEntity&gt; l) {
      for (NewsEntity n:l){
          int size = list.size();
          list.add(size,n);
          notifyItemInserted(size);
      }
  
  }
  </code></pre>
  <hr />
  <p>At each request list get populated with 10 items.<br><br>
  Sorry for this worst explanation of my problem.</p>