title: Error: Invalid conversion from throwing function of type '(_) throws -> ()' to non-throwing function type '(DataSnapshot) -> Void'
body: <p>Here’s my code:</p>
  
  <pre><code>func loadData() {
      ref.child(currentUserID!).observe(.childAdded) {
          (snapshot) in
          let snapshotValue = try? snapshot.value as? [String: AnyObject]
          if let item = try TableViewModel(id: snapshot.key, likeLabel: self.likeLabel, playLabelString: self.playLabelString, json: snapshotValue) {
              self.items.append(item)
          }            
          self.tableViewModel = self.items.reversed() as [TableViewModel]
      }
  }
  </code></pre>
  
  <p>I can’t get my head around the following error:</p>
  
  <blockquote>
    <p>Invalid conversion from throwing function of type <code>(_) throws -&gt; ()</code> to non-throwing function type<code>(DataSnapshot) -&gt; Void</code></p>
  </blockquote>
  
  <p>in the following line:</p>
  
  <pre><code>ref.child(currentUserID!).observe(.childAdded) {
  </code></pre>
  
  <p>Please help.</p>