title: combining tap event of 3 buttons with rxSwift
body: <p>I have 3 buttons </p>
  
  <pre class="lang-swift prettyprint-override"><code>@IBOutlet weak var editGeomButton: UIButton! // 1
  @IBOutlet weak var editDataButton: UIButton! // 2
  @IBOutlet weak var deleteDataButton: UIButton! // 3
  </code></pre>
  
  <p>On click of any of this buttons I want below method to be called. With the proper numbers.</p>
  
  <pre class="lang-swift prettyprint-override"><code>func didTap() -&gt; Observable&lt;Int&gt; {
  
  }
  
  didTap().subscribe(onNext: { (tag) in
      switch tag {
      case 1:
          print("Did tap Edit Geom")
      case 2:
          print("Did tap Edit Data")
      case 3:
          print("Did tap Delete geom")
      default:
          print("Invalid tap")
      }
  }).disposed(by: disposeBag)
  </code></pre>
  
  <p>Please help with the code to write in didTap method using Observable? I think this can be achieved using combine operator. But I don't understand how to code this.</p>