title: How to initialize interface in the mainActivity
body: <p>I have a mainActivity which uses bluetooth, and I have another class that extends BaseExpandableListAdapter. What I want to do is, when a specific action occurs
  in the mainActivity class, the bluetooth adapter should be passed to the class that extends BaseExpandableListAdapter.</p>
  
  <p>To achieve that, I've created an interface IBTAdapterPasser as shown below and I've passed the adapter from the mainActivity to the iBTAdapterPasser as shown below.
  My question is, how should I initialize the iBTAdapterObserver object in the mainActivity?</p>
  
  <p><strong>IBTAdapterPasser</strong>:</p>
  
  <pre><code>public interface IBTAdapterPasser {
      public void onDicoveryFinished(BluetoothAdapter btAdapter);
  }
  </code></pre>
  
  <p><strong>in the mainActivity class</strong>:</p>
  
  <pre><code>this.iBTAdapterObserver.onDicoveryFinished(this.mBTAdapter);
  </code></pre>
  
  <p><strong>MyExpandableListAdapter class</strong></p>
  
  <pre><code>@Override
  public void onDicoveryFinished(BluetoothAdapter btAdapter) {
      // TODO Auto-generated method stub
      this.mBTAdapter = btAdapter;
  }
  </code></pre>