code: def data(self, key=None, **kwargs):
          
          self.content_data.update(kwargs)
          if key:
              return self.content_data[key]
          if not kwargs:
              return self.content_data
          return self
docs: Adds or retrieve extra data to this element, this data will not be rendered.
          Every tag have a _data attribute (dict), if key is given _data[key] is returned.
          Kwargs are used to udpate this Tag's _data.