code: def get_md5_from_hexdigest(self, md5_hexdigest):
          
          import binascii
          digest = binascii.unhexlify(md5_hexdigest)
          base64md5 = base64.encodestring(digest)
          if base64md5[-1] == '\n':
              base64md5 = base64md5[0:-1]
          return (md5_hexdigest, base64md5)
docs: A utility function to create the 2-tuple (md5hexdigest, base64md5)
          from just having a precalculated md5_hexdigest.