Run the client using a background thread.

def start(self, build_requests=None, callback=None):
        """
        Run the client using a background thread.
        """
        if callback:
            self.callback = callback
        if build_requests:
            self.build_requests = build_requests

        # spin off requester thread
        self.sw = threading.Thread(target=self.run)
        self.sw.start()