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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 setup(self):
 """Check if the bluetooth controller is available."""

        try:
            subprocess.check_output(["hcitool", "clock"],
                                    stderr=subprocess.STDOUT)
        except subprocess.CalledProcessError:
            raise BackendError("'hcitool clock' returned error. Make sure "
                               "your bluetooth device is powered up with "
                               "'hciconfig hciX up'.")
        except OSError:
            raise BackendError("'hcitool' could not be found, make sure you "
                               "have bluez-utils installed.")