class Sass::Tree::Visitors::Convert

def selector_to_sass(sel)
  sel.map do |r|
    if r.is_a?(String)
      r.gsub(/(,[ \t]*)?\n\s*/) {$1 ? $1 + "\n" : " "}
    else
      "\#{#{r.to_sass(@options)}}"
    end
  end.join
end