def GetUserTimeline(self, user=None, count=None, since=None, since_id=None):
    '''Fetch the sequence of public twitter.Status messages for a single user.

    The twitter.Api instance must be authenticated if the user is private.

    Args:
      user:
        either the username (short_name) or id of the user to retrieve.  If
        not specified, then the current authenticated user is used. [optional]
      count: the number of status messages to retrieve [optional]
      since:
        Narrows the returned results to just those statuses created
        after the specified HTTP-formatted date. [optional]
      since_id:
        Returns only public statuses with an ID greater than (that is,
        more recent than) the specified ID. [Optional]

    Returns:
      A sequence of twitter.Status instances, one for each message up to count
    '''
    try:
      if count:
        int(count)
    except:
      raise TwitterError("Count must be an integer")
    parameters = {}
    if count:
      parameters['count'] = count
    if since:
      parameters['since'] = since
    if since_id:
      parameters['since_id'] = since_id
    if user:
      url = TWITTER_API_ROOT + 'statuses/user_timeline/%s.json' % user
    elif not user and not self._username:
      raise TwitterError("User must be specified if API is not authenticated.")
    else:
      url = TWITTER_API_ROOT + 'statuses/user_timeline.json'
    json = self._FetchUrl(url, parameters=parameters)
    data = simplejson.loads(json)
    self._CheckForTwitterError(data)
    return [Status.NewFromJsonDict(x) for x in data]
Fetch the sequence of public twitter.Status messages for a single user.

    The twitter.Api instance must be authenticated if the user is private.

    Args:
      user:
        either the username (short_name) or id of the user to retrieve.  If
        not specified, then the current authenticated user is used. [optional]
      count: the number of status messages to retrieve [optional]
      since:
        Narrows the returned results to just those statuses created
        after the specified HTTP-formatted date. [optional]
      since_id:
        Returns only public statuses with an ID greater than (that is,
        more recent than) the specified ID. [Optional]

    Returns:
      A sequence of twitter.Status instances, one for each message up to count
    
twitter/twitter.py