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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 just_smart_bibtools(bib_style, aux, bib):
 """Tectonic has taken over most of the features that this tool used to provide, but here's a hack to keep my smart .bib file generation working. """

    extradir = Path('.bibtex')
    extradir.ensure_dir(parents=True)

    bib_export(bib_style, aux, extradir / 'ZZ_bibtools.bib',
               no_tool_ok=True, quiet=True, ignore_missing=True)
    merge_bibtex_with_aux(aux, bib, extradir)