   with data attributes' names and values as the first element
   in the tag's attributes keyword list:
 
-      iex> tag(:input, [{:data, [foo: "bar"]}, id: "some_id"])
-      {:safe, [60, "input", [[32, "data-foo", 61, 34, "bar", 34], [32, "id", 61, 34, "some_id", 34]], 62]}
+      iex> safe_to_string tag(:input, [data: [foo: "bar"], id: "some_id"])
+      "<input data-foo=\"bar\" id=\"some_id\">"
 
   ## Boolean values
 

defmodule Phoenix.HTML.Tag do
  @moduledoc ~S"""
  Helpers related to producing HTML tags within templates.
  """

  import Phoenix.HTML

  @doc ~S"""
  Creates an HTML tag with the given name and options.

      iex> safe_to_string tag(:br)
      "<br>"
      iex> safe_to_string tag(:input, type: "text", name: "user_id")
      "<input name=\"user_id\" type=\"text\">"

  ## Data attributes

