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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 __ensure_suffix_stem(t, suffix):
 """ Ensure that the target t has the given suffix, and return the file's stem. """

    tpath = str(t)
    if not tpath.endswith(suffix):
        stem = tpath
        tpath += suffix
        
        return tpath, stem
    else:
        stem, ext = os.path.splitext(tpath)
    
    return t, stem