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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 switch(self, val=None):
 """ Set the state of the switch. If the armed state is set to False, the function does nothing. :param val: Boolean. The value to set the switch state to. When None, the switch will be set to the opposite of its current state. :return: Boolean. Returns True if operation was successful (i.e. the switch was armed before this was called) """

        if self._armed:
            if val is None:
                val = not self._switched
            self._switched = val
            self._armed = False
            return True
        else:
            return False