docs: def add_params(endpoint, params):
      """
      Combine query endpoint and params.
  
      Example::
  
          >>> add_params("https://www.google.com/search", {"q": "iphone"})
          https://www.google.com/search?q=iphone
      """
      p = PreparedRequest()
      p.prepare(url=endpoint, params=params)
      if PY2:  # pragma: no cover
          return unicode(p.url)
      else:  # pragma: no cover
          return p.url