     |> find_interpolations(source)
     |> Enum.reject(&is_nil/1)
     |> add_to_col_start_and_end(padding_in_first_line)
+  end
+
+  # Elixir 1.13+
+  defp handle_heredoc({atom, {line_no, col_start, col_end}, _, list}, source) do
+    handle_heredoc({atom, {line_no, col_start, col_end}, list}, source)
   end
 
   defp find_interpolations(list, source) when is_list(list) do

  end

  #
  # Elixir >= 1.11.0
  #
  defp map_interpolations(

    handle_atom_string_or_sigil(token, list, source)
  end

  defp map_interpolations(token, _source) do 
    []
  end

  defp handle_atom_string_or_sigil(_token, list, source) do
    find_interpolations(list, source)
