code: def use_quandl_data(self, authtoken):
          
          dfs = {}
          st = self.start.strftime("%Y-%m-%d")
          at = authtoken
          for pair in self.pairs:
              symbol = "".join(pair)
              qsym = "CURRFX/{}".format(symbol)
              dfs[symbol] = qdl.get(qsym,authtoken=at, trim_start=st)['Rate']
              
          self.build_conversion_table(dfs)
docs: Use quandl data to build conversion table