code: def get_quantity(self) -> Decimal:
          
          from pydatum import Datum
          # Use today's date but reset hour and lower.
          today = Datum()
          today.today()
          today.end_of_day()
          return self.get_num_shares_on(today.value)
docs: Returns the number of shares for the given security.
          It gets the number from all the accounts in the book.