docs: def stdrepr(self, obj, *, cls=None, tag='span'):
          """
          Standard representation for objects, used when there is no
          handler for its type in type_handlers on the HRepr object,
          and no __hrepr__ method on obj. For an object of class 'klass',
          the result is:
  
          ``<span class="hrepr-klass">{escape(str(obj))}</span>``
  
          Where ``{escape(str(obj))}`` is the HTML-escaped string representation
          of the object.
  
          Args:
              obj: The object to represent.
              cls (optional): The class name for the representation. If None,
                  stdrepr will use ``'hrepr-' + obj.__class__.___name__``
              tag (optional): The tag for the representation, defaults to
                  'span'.
          """
          if cls is None:
              cls = f'hrepr-{obj.__class__.__name__}'
          return getattr(self.H, tag)[cls](str(obj))