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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 prepare_output(d):
 """Clean pre-existing links in output directory."""

    outDir = os.path.join(d, 'inorder')
    if not os.path.exists(outDir):
        os.mkdir(outDir)
    for f in os.listdir(outDir):
        f = os.path.join(outDir, f)
        if os.path.islink(f):
            os.remove(f)
    return outDir