 
   """
 
-  @spec find(binary() | html_tree(), css_selector()) :: html_tree
+  @spec find(binary() | html_tree() | html_node(), css_selector()) :: html_tree
 
   def find(html, selector) when is_binary(html) do
     IO.warn(

      [{"div", [{"id", "b"}, {"class", "name"}], []}]

  """
  @spec attr(binary | html_tree, css_selector(), binary, (binary -> binary)) :: html_tree

  def attr(html_elem_tuple, selector, attribute_name, mutation) when is_tuple(html_elem_tuple) do
    attr([html_elem_tuple], selector, attribute_name, mutation)


  """

  @spec attribute(binary | html_tree | html_node, binary, binary) :: list

  def attribute(html, selector, attribute_name) do
    html
