docs: def jsmin(js, **kwargs):
      """
      returns a minified version of the javascript string
      """
      if not is_3:        
          if cStringIO and not isinstance(js, unicode):
              # strings can use cStringIO for a 3x performance
              # improvement, but unicode (in python2) cannot
              klass = cStringIO.StringIO
          else:
              klass = StringIO.StringIO
      else:
          klass = io.StringIO
      ins = klass(js)
      outs = klass()
      JavascriptMinify(ins, outs, **kwargs).minify()
      return outs.getvalue()