title: Adding table to navigation controller view programatically doesnt work
body: <p>When attempting to add a table to cover the entire view of a view controller like so:</p>
  
  <pre><code>func setConstraints(){
  
      self.view.addSubview(statisticsTable);
  
      statisticsTable.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true;
      statisticsTable.rightAnchor.constraint(equalTo: self.view.rightAnchor).isActive = true;
      statisticsTable.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true;
      statisticsTable.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true;
  }
  </code></pre>
  
  <p>The table doesnt display. Am i correct to assume that by topAnchor in the context of a navigation controller we mean the top part of the view contrller view ( which is where the navigatio bar ends? ). This looks quite simple so im clearly missing something obvious here. Thank you.</p>