code: def _setup_features(self):
          
          features = self._features = self.declaration.features
          if not features:
              return
          if features & Feature.FocusTraversal:
              self.hook_focus_traversal()
          if features & Feature.FocusEvents:
              self.hook_focus_events()
          if features & Feature.DragEnabled:
              self.hook_drag()
          if features & Feature.DropEnabled:
              self.hook_drop()
              
          features = self._extra_features
          if features & GraphicFeature.WheelEvent:
              self.hook_wheel()
          if features & GraphicFeature.DrawEvent:
              self.hook_draw()
docs: Setup the advanced widget feature handlers.