def stylesheet_link(src_url, src_path=None, cache_bust=None, content='<STR_LIT>', extra_attrs=None):
if cache_bust:<EOL><INDENT>append_suffix = get_cache_buster(src_path=src_path, method=cache_bust)<EOL>delim = '<STR_LIT:&>' if '<STR_LIT:?>' in src_url else '<STR_LIT:?>'<EOL>src_url += delim + append_suffix<EOL><DEDENT>attrs = {<EOL>'<STR_LIT>': src_url,<EOL>'<STR_LIT>': '<STR_LIT>',<EOL>}<EOL>if extra_attrs:<EOL><INDENT>attrs.update(extra_attrs)<EOL><DEDENT>return tag('<STR_LIT>', content=content, attrs=attrs)<EOL>
Helper for programmatically building HTML StyleSheet source include
    links, with optional cache busting.

    :param src_url:
        Goes into the `src` attribute of the `<link src="...">` tag.

    :param src_path:
        Optional filesystem path to the source file, used when `cache_bust` is
        enabled.

    :param content:
        Optional content of the DOM element. If `None`, then the element is
        self-closed.

    :param cache_bust:
        Optional method to use for cache busting. Can be one of: importtime,
        md5, or mtime. If the value is md5 or mtime, then `src_path` must be
        supplied.


    Example::

        >>> stylesheet_link('/static/css/media.css')
        u'<link href="/static/css/media.css" rel="stylesheet"></link>'