Set the dead lock time.

        :Parameters:
            #. deadLock (number): The time delay judging if the lock was left out mistakenly
               after a system crash or other unexpected reasons. Normally Locker is stable
               and takes care of not leaving any locking file hanging even it crashes or it
               is forced to stop by a user signal.

def set_dead_lock(self, deadLock):
        """
        Set the dead lock time.

        :Parameters:
            #. deadLock (number): The time delay judging if the lock was left out mistakenly
               after a system crash or other unexpected reasons. Normally Locker is stable
               and takes care of not leaving any locking file hanging even it crashes or it
               is forced to stop by a user signal.
        """
        try:
            deadLock = float(deadLock)
            assert deadLock>=0
        except:
            raise Exception('deadLock must be a positive number')
        self.__deadLock = deadLock