Stop spinner, compose last frame and 'freeze' it.

def _freeze(self, final_text):
        """Stop spinner, compose last frame and 'freeze' it."""
        text = to_unicode(final_text)
        self._last_frame = self._compose_out(text, mode="last")

        # Should be stopped here, otherwise prints after
        # self._freeze call will mess up the spinner
        self.stop()
        sys.stdout.write(self._last_frame)