If this is ``""`` or ``None``, Unicode strings will be written
to the output file, which most file-like objects do not support.
+ For example, `pygments.highlight()` will return a Unicode string if
+ called with no `outfile` argument and a formatter that has `encoding`
+ set to ``None`` because it uses a `StringIO.StringIO` object that
+ supports Unicode arguments to `write()`. Using a regular file object
The `HtmlFormatter` and `LatexFormatter` classes support these options: