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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_friends_list(self, steamID, relationship='all', format=None):
 """Request the friends list of a given steam ID filtered by role. steamID: The user ID relationship: Type of friend to request (all, friend) format: Return format. None defaults to json. (json, xml, vdf) """

        parameters = {'steamid' : steamID, 'relationship' : relationship}
        if format is not None:
            parameters['format'] = format
        url = self.create_request_url(self.interface, 'GetFriendsList', 1,
            parameters)
        data = self.retrieve_request(url)
        return self.return_data(data, format=format)