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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 unregisterHandler(self, fh):
 """ Unregister a file descriptor. Clean data, if such operation has been scheduled. Parameters fh : int File descriptor. """


        try:
            self.fds.remove(fh)

        except KeyError:
            pass

        self.lock.acquire()

        try:
            self.data.rollover() # rollover data on close.

        finally:
            self.lock.release()

        if self.closing and not self.fds:
            self.data.close()