title: How to set enum AllowTabbedDocks with PyQt5
body: <p>I want to make a QMainWindow for my PyQt5 app. I want to use <code>AllowTabbedDocks</code>, but for this I need to set <code>AllowTabbedDocks</code> to <code>True</code>. I cannot figue out how to do this.</p>
  
  <p>From the Qt documenttation, I found these two methods:</p>
  
  <pre><code>class MainWindow(QMainWindow):
      def __init__(self, url):
          super(MainWindow, self).__init__()
          .....
          self.setDockOption()
          self.DockOptions()
  </code></pre>
  
  <p>Available flags in QMainWindow class are as follow:</p>
  
  <pre><code>AllowNestedDocks = 2
  AllowTabbedDocks = 4
  AnimatedDocks = 1
  ForceTabbedDocks = 8
  GroupedDragging = 32
  VerticalTabs = 16
  </code></pre>
  
  <p>My question is how can I use:</p>
  
  <pre><code>dockOptions()
  setDockOption()
  </code></pre>
  
  <p>of the <code>QMainWindow</code> class? My question may be weird, because I am unable to understand properly.</p>