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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 set_if_missing(cfg,section,option,value):
 """If the given option is missing, set to the given value."""

    try:
        cfg.get(section,option)
    except NoSectionError:
        cfg.add_section(section)
        cfg.set(section,option,value)
    except NoOptionError:
        cfg.set(section,option,value)