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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 clear_host_port(self):
 """Stops the adb port forwarding of the host port used by this client. """

        if self.host_port:
            self._adb.forward(['--remove', 'tcp:%d' % self.host_port])
            self.host_port = None