def total_picos(self) -> _NUMERIC_OUTPUT_TYPE:
        """Returns the number of picoseconds that the duration spans."""
        val = sum(a * b for a, b in zip(self._time_vals, self._multipliers))
        return float(val) if isinstance(val, np.number) else val
Returns the number of picoseconds that the duration spans.
cirq-core/cirq/value/duration.py