docs: def delete(self, symbol, date_range=None):
          """
          Delete all chunks for a symbol.
  
          Which are, for the moment, fully contained in the passed in
          date_range.
  
          Parameters
          ----------
          symbol : `str`
              symbol name for the item
          date_range : `date.DateRange`
              DateRange to delete ticks in
          """
          query = {SYMBOL: symbol}
          date_range = to_pandas_closed_closed(date_range)
          if date_range is not None:
              assert date_range.start and date_range.end
              query[START] = {'$gte': date_range.start}
              query[END] = {'$lte': date_range.end}
          else:
              # delete metadata on complete deletion
              self._metadata.delete_one({SYMBOL: symbol})
          return self._collection.delete_many(query)