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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 _resolve_hardware_count(self):
 """ Calculate amount of hardware resources. :return: Nothing, adds results to self._hardware_count """

        length = len([d for d in self._dut_requirements if d.get("type") in ["hardware",
                                                                             "serial", "mbed"]])
        self._hardware_count = length