'Release the lock.
Removes the PID file to release the lock, or raises an
error if the current process does not hold the lock.'

def release(self):

    if (not self.is_locked()):
        raise NotLocked(('%s    is    not    locked' % self.path))
    if (not self.i_am_locking()):
        raise NotMyLock(('%s    is    locked,    but    not    by    me' % self.path))
    remove_existing_pidfile(self.path)
