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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 _write(self, frame):
 """ Write a YubiKeyFrame to the USB HID. Includes polling for YubiKey readiness before each write. """

        for data in frame.to_feature_reports(debug=self.debug):
            debug_str = None
            if self.debug:
                (data, debug_str) = data
            # first, we ensure the YubiKey will accept a write
            self._waitfor_clear(yubikey_defs.SLOT_WRITE_FLAG)
            self._raw_write(data, debug_str)
        return True