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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 wake(self):
 """ Wake the INA219 from power down mode """

        configuration = self._read_configuration()
        self._configuration_register(configuration | 0x0007)
        # 40us delay to recover from powerdown (p14 of spec)
        time.sleep(0.00004)