code: def _GetNormalizedTimestamp(self):
      
      if self._normalized_timestamp is None:
        if self._timestamp is not None:
          self._normalized_timestamp = decimal.Decimal(self._timestamp)
  
          if self.fraction_of_second is not None:
            fraction_of_second = decimal.Decimal(self.fraction_of_second)
  
            if self._precision == dfdatetime_definitions.PRECISION_1_NANOSECOND:
              fraction_of_second /= self._NANOSECONDS_PER_SECOND
            else:
              fraction_of_second /= self._100_NANOSECONDS_PER_SECOND
  
            self._normalized_timestamp += fraction_of_second
  
      return self._normalized_timestamp
docs: Retrieves the normalized timestamp.
  
      Returns:
        decimal.Decimal: normalized timestamp, which contains the number of
            seconds since January 1, 1970 00:00:00 and a fraction of second used
            for increased precision, or None if the normalized timestamp cannot be
            determined.