def add(self, key, value):
        """
            Creates a space separated string of attributes.  Mostly for the
            "class" attribute.
        """
        if key.endswith('_'):
            key = key[:-1]
        if key in self.attributes:
            self.attributes[key] = self.attributes[key] + ' ' + value
        else:
            self.attributes[key] = value
Creates a space separated string of attributes.  Mostly for the
            "class" attribute.