   empty string in case the device has reached EOF.
   """
   @spec read(device, :all | :line | non_neg_integer) :: chardata | nodata
-  def read(device \\ group_leader(), line_or_chars)
+  def read(device \\ :stdio, line_or_chars)
 
   def read(device, :all) do
     do_read_all(map_dev(device), "")

  as it will return the wrong result.
  """
  @spec binwrite(device, iodata) :: :ok | {:error, term}
  def binwrite(device \\ group_leader(), item) when is_iodata(item) do
    :file.write map_dev(device), item
  end



  """
  @spec write(device, chardata | String.Chars.t) :: :ok
  def write(device \\ :stdio, item) do
    :io.put_chars map_dev(device), to_chardata(item)
  end

