       {:ok, "Something “smart” and … —you get it\\!\n"}
 
       iex> callback = fn (results) ->
-      iex>   Enum.map(results, &String.strip/1) |> Enum.join("%%joiner%%")
+      iex>   Enum.map(results, &String.trim/1) |> Enum.join("%%joiner%%")
       iex> end
       iex> Cmark.to_commonmark(["en-dash --", "ellipsis..."], callback, [:smart])
       "en-dash –%%joiner%%ellipsis…"

  ## Examples

      iex> Cmark.to_xml(~s(Use option to enable "smart" quotes.), [:smart])
      "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<!DOCTYPE document SYSTEM \"CommonMark.dtd\">
      <document xmlns=\"http://commonmark.org/xml/1.0\">\n  <paragraph>\n    <text>Use option to enable </text>
          <text>“</text>\n    <text>smart</text>\n    <text>”</text>\n    <text> quotes</text>\n    <text>.</text>
        </paragraph>\n</document>\n"

      iex> Cmark.to_xml([~s(Something "smart"), ~s(em---dashed)], [:smart])
      ["<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<!DOCTYPE document SYSTEM \"CommonMark.dtd\">
      <document xmlns=\"http://commonmark.org/xml/1.0\">\n  <paragraph>\n    <text>Something </text>
          <text>“</text>\n    <text>smart</text>\n    <text>”</text>\n  </paragraph>\n</document>\n",
      "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<!DOCTYPE document SYSTEM \"CommonMark.dtd\">
      <document xmlns=\"http://commonmark.org/xml/1.0\">\n  <paragraph>\n    <text>em</text>
          <text>—</text>\n    <text>dashed</text>\n  </paragraph>\n</document>\n"]

  -----



  ## Examples

      iex> callback = fn (result) -> "XML is #{result}" |> String.trim end
      iex> Cmark.to_xml("test", callback)
      "XML is <?xml version=\"1.0\" encoding=\"UTF-8\"?>
      <!DOCTYPE document SYSTEM \"CommonMark.dtd\">
      <document xmlns=\"http://commonmark.org/xml/1.0\">
        <paragraph>
          <text xml:space=\"preserve\">test</text>
        </paragraph>
      </document>"

      iex> callback = fn (results) ->
      iex>   Enum.map(results, &String.trim/1) |> Enum.join("<joiner>")
      iex> end
      iex> Cmark.to_xml(["list", "test"], callback)
      "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
      <!DOCTYPE document SYSTEM \"CommonMark.dtd\">
      <document xmlns=\"http://commonmark.org/xml/1.0\">
        <paragraph>
          <text xml:space=\"preserve\">list</text>
        </paragraph>
      </document><joiner><?xml version=\"1.0\" encoding=\"UTF-8\"?>
      <!DOCTYPE document SYSTEM \"CommonMark.dtd\">
      <document xmlns=\"http://commonmark.org/xml/1.0\">
        <paragraph>
          <text xml:space=\"preserve\">test</text>
        </paragraph>
      </document>"

  """
