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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, dataUrl):
 """ Populates the instance variables of this ReferencSet from the data URL. """

        self._dataUrl = dataUrl
        fastaFile = self.getFastaFile()
        for referenceName in fastaFile.references:
            reference = HtslibReference(self, referenceName)
            # TODO break this up into chunks and calculate the MD5
            # in bits (say, 64K chunks?)
            bases = fastaFile.fetch(referenceName)
            md5checksum = hashlib.md5(bases).hexdigest()
            reference.setMd5checksum(md5checksum)
            reference.setLength(len(bases))
            self.addReference(reference)