code: def attribute_node(self, name, ns_uri=None):
          
          attr_impl_node = self.adapter.get_node_attribute_node(
              self.impl_node, name, ns_uri)
          return self.adapter.wrap_node(
              attr_impl_node, self.adapter.impl_document, self.adapter)
docs: :param string name: the name of the attribute to return.
          :param ns_uri: a URI defining a namespace constraint on the attribute.
          :type ns_uri: string or None
  
          :return: this element's attributes that match ``ns_uri`` as
              :class:`Attribute` nodes.