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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 use_setuptools( version=DEFAULT_VERSION, download_base=DEFAULT_URL, to_dir=DEFAULT_SAVE_DIR, download_delay=15):
 """ Ensure that a setuptools version is installed. Return None. Raise SystemExit if the requested version or later cannot be installed. """

    to_dir = os.path.abspath(to_dir)

    # prior to importing, capture the module state for
    # representative modules.
    rep_modules = 'pkg_resources', 'setuptools'
    imported = set(sys.modules).intersection(rep_modules)

    try:
        import pkg_resources
        pkg_resources.require("setuptools>=" + version)
        # a suitable version is already installed
        return
    except ImportError:
        # pkg_resources not available; setuptools is not installed; download
        pass
    except pkg_resources.DistributionNotFound:
        # no version of setuptools was found; allow download
        pass
    except pkg_resources.VersionConflict as VC_err:
        if imported:
            _conflict_bail(VC_err, version)

        # otherwise, unload pkg_resources to allow the downloaded version to
        #  take precedence.
        del pkg_resources
        _unload_pkg_resources()

    return _do_download(version, download_base, to_dir, download_delay)