Return string representation of this.

        Used in start tag of HTML representation of the Element node.

def html(self) -> str:
        """Return string representation of this.

        Used in start tag of HTML representation of the Element node.
        """
        if self._owner and self.name in self._owner._special_attr_boolean:
            return self.name
        else:
            value = self.value
            if isinstance(value, str):
                value = html_.escape(value)
            return '{name}="{value}"'.format(name=self.name, value=value)