How to use the cellbrowser.loadConfig function in cellbrowser

def cbTrackHub(options):
    " make track hub given meta file and directory with bam files "
    if options.init:
        cellbrowser.copyPkgFile("sampleConfig/cellbrowser.conf")
        sys.exit(0)

    if isfile(options.inConf):
        conf = cellbrowser.loadConfig(options.inConf)

        db = conf["ucscDb"]
        inMatrixFname = conf["exprMatrix"]
        metaFname = conf["meta"]
        clusterFieldName = conf["clusterField"]
        clusterOrderFile = conf.get("clusterOrder")
        bamDir = conf.get("bamDir", "bam")
        fixDot = conf.get("fixDot", False)
        email = conf.get("hubEmail", CBEMAIL)
        geneType = conf["geneIdType"]
        outDir = conf["hubDir"]
        unitName = conf.get("unit", "TPM")
        hubUrl = conf.get("hubUrl", "")
        refHtmlFname = conf.get("refHtml", None)

        # use name, shortLabel or hubName from conf