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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 populateFromDirectory(self, vcfDirectory):
 """ Populates this VariantSet by examing all the VCF files in the specified directory. This is mainly used for as a convenience for testing purposes. """

        pattern = os.path.join(vcfDirectory, "*.vcf.gz")
        dataFiles = []
        indexFiles = []
        for vcfFile in glob.glob(pattern):
            dataFiles.append(vcfFile)
            indexFiles.append(vcfFile + ".tbi")
        self.populateFromFile(dataFiles, indexFiles)