title: How can I include two Model Class Tracks and Artists in one FirestoreRecyclerAdapter in Android?
body: <p>My android project has <strong>two models</strong> - <em>Track and Artist</em>.
  <br>Track is used to get the information related to Track and Artist is used to get the details related to Artist.</p>
  
  <p>Here is the sample code for the each model:<br>
  <strong>Track.class</strong></p>
  
  <pre><code>public class Track {
      private int track_ID;
      private String title;
      private String artist;
      private String songWriter;
      private String lyrics;
      private String album;
      private String language;
      private int views;
      private int year;
      private String albumArt;
      private String videoURL;
      private String shareURL;
  
      public Track(){
          //Empty Constructor
      }
  </code></pre>
  
  <p><strong>Artist.class</strong></p>
  
  <pre><code>private int artist_ID;
      private String name;
      private boolean verified;
      private String artistProfilePic;
  
      public Artist(){
          //Empty Constructor
      }
  
  </code></pre>
  
  <p>In the code below <em>I am only able to use Track Model</em></p>
  
  <pre><code>public class SongAdapter extends FirestoreRecyclerAdapter&lt;Track, SongAdapter.SongHolder&gt; {
  </code></pre>
  
  <p>My problem is I am not able to use both the model in one FirestoreRecyclerAdapter. </p>
  
  <p>How can I do it?</p>