code: def init_widget(self):
          
          super(AndroidPicker, self).init_widget()
          d = self.declaration
          w = self.widget
          if d.items:
              self.set_items(d.items)
          else:
              if d.max_value:
                  self.set_max_value(d.max_value)
              if d.min_value:
                  self.set_min_value(d.min_value)
          self.set_value(d.value)
          if d.wraps:
              self.set_wraps(d.wraps)
  
          if d.long_press_update_interval:
              self.set_long_press_update_interval(d.long_press_update_interval)
  
          w.setOnValueChangedListener(w.getId())
          w.onValueChange.connect(self.on_value_change)
docs: Set the checked state after all children have
          been populated.