code: def fetch(self):
          
          self._validate_params()
          if self.islast:
              data = super(DailySummaryReader, self).fetch()
          else:
              data = self._fetch_dates()
          if self.output_format == 'pandas':
              data.set_index('date', inplace=True)
              return data
          else:
              return data
docs: Unfortunately, IEX's API can only retrieve data one day or one month
          at a time. Rather than specifying a date range, we will have to run
          the read function for each date provided.
  
          :return: DataFrame