title: How to retrieve the middle value of a node
body: <p>I have a Firebase structure like this</p>
  
  <pre><code>"lists" : {
    "-LlBpKy9Q8UfCXCweM4b" : {
      "-LlBy-5Q9HX0YLFkBkev" : {
        "6416739414706" : {
          "addedDate" : "12-8-2019 at: 20:45:38",
          "amount" : 1,
          "contentSize" : 100,
          "objectProducer" : "Nailman",
          "objectType" : "Nails",
          "unit" : "Pcs"
        }
      }
    }
  }
  </code></pre>
  
  <p>I would like to retrieve the objectID ( 6416739414706 ) I retrieve all other values like this:</p>
  
  <pre><code>ref?.observeSingleEvent(of: .value, with: { (snapshot) in
      for child in snapshot.children.allObjects as! [DataSnapshot] {
      // print(child.value)
      guard let dict = child.value as? [String: AnyObject] else { return }
      self.objectProducer.append(dict["objectProducer"] as! String)
      self.objectType.append(dict["objectType"] as! String)
      self.contentSize.append(dict["contentSize"] as! Double)
      self.objectMeasureUnit.append(dict["unit"] as! String)
      self.objectAmount.append(dict["amount"] as! Double)
      self.objectLastAdded.append(dict["addedDate"] as! String)     
  }
  </code></pre>
  
  <p>This works fine, but I have not been able to retrieve the objectID. How can this be done?</p>