code: def select_by_value(self, value):
          
          self._selected_key = None
          self._selected_item = None
          for k in self.children:
              item = self.children[k]
              item.attributes['selected'] = False
              if value == item.get_value():
                  self._selected_key = k
                  self._selected_item = item
                  self._selected_item.attributes['selected'] = True
docs: Selects an item by the text content of the child.
  
          Args:
              value (str): Text content of the item that have to be selected.