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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 populateFromFile(self, dataUrls, indexFiles):
 """ Populates this variant set using the specified lists of data files and indexes. These must be in the same order, such that the jth index file corresponds to the jth data file. """

        assert len(dataUrls) == len(indexFiles)
        for dataUrl, indexFile in zip(dataUrls, indexFiles):
            varFile = pysam.VariantFile(dataUrl, index_filename=indexFile)
            try:
                self._populateFromVariantFile(varFile, dataUrl, indexFile)
            finally:
                varFile.close()