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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 fail(p_queue, host=None):
    if host is not None:
        return _path(_c.FSQ_FAIL, root=_path(host, root=hosts(p_queue)))
    '''Construct a path to the fail dir for a queue'''
    return _path(p_queue, _c.FSQ_FAIL)