   In case one wants to access the original `Keyword`, it can be done
   by accessing `Elixir`:
 
-      Keyword.values   #=> uses MyKeyword.values
+      Keyword.values #=> uses MyKeyword.values
       Elixir.Keyword.values #=> uses Keyword.values
 
   Notice that calling `alias` without the `:as` option automatically


  Both warning behaviours could be changed by explicitly
  setting the `:warn` option to `true` or `false`.
  """
  defmacro alias(module, opts), do: error!([module, opts])


  defmacro unquote(:.)(left, right), do: error!([left, right])

  @doc """
  `alias/2` is used to setup aliases, often useful with modules' names.

  ## Examples

  `alias/2` can be used to set up an alias for any module:

      defmodule Math do
        alias MyKeyword, as: Keyword
