title: How to use AVAudioNodeTapBlock in a tap in AVAudioEngine.
body: <p>I am trying to install a tap on an AVAudioEngine. I have the current code:</p>
  
  <pre><code>    guard let engine = engine, let input = engine.inputNode else {
          print("error!")
          return
      }
      let format = input.inputFormat(forBus: 0)
      let bufferSize = 4096
      input.installTap(onBus: 0, bufferSize: AVAudioFrameCount(bufferSize), format: format, block: )
  </code></pre>
  
  <p>I am unsure on what goes in the block. There isn't much documentation on this. I have found this: <a href="https://developer.apple.com/reference/avfoundation/avaudionodetapblock?language=objc" rel="nofollow noreferrer">https://developer.apple.com/reference/avfoundation/avaudionodetapblock?language=objc</a></p>
  
  <p>Could someone explain how to use this?</p>
  
  <p>Thanks,</p>
  
  <p>Feras A. </p>