'Returns a list of twitter user id\'s for every person
that is following the specified user.
Args:
user_id:
The id of the user to retrieve the id list for. [Optional]
screen_name:
The screen_name of the user to retrieve the id list for. [Optional]
cursor:
Specifies the Twitter API Cursor location to start at.
Note: there are pagination limits. [Optional]
stringify_ids:
if True then twitter will return the ids as strings instead of
integers. [Optional]
count:
The number of user id\'s to retrieve per API request. Please be aware
that this might get you rate-limited if set to a small number.
By default Twitter will retrieve 5000 UIDs per call. [Optional]
total_count:
The total amount of UIDs to retrieve. Good if the account has many
followers and you don\'t want to get rate limited. The data returned
might contain more UIDs if total_count is not a multiple of count
(5000 by default). [Optional]
Returns:
A list of integers, one for each user id.'

def GetFollowerIDs(self, user_id=None, screen_name=None, cursor=None, stringify_ids=False, count=None, total_count=None):

    url = ('%s/followers/ids.json' % self.base_url)
    return self._GetFriendFollowerIDs(url, user_id, screen_name, cursor, stringify_ids, count, total_count)
