def update(self, sequence=None, **mapping):
        """Add multiple elements to the fact."""
        if sequence is not None:
            if isinstance(sequence, dict):
                for slot in sequence:
                    self[slot] = sequence[slot]
            else:
                for slot, value in sequence:
                    self[slot] = value
        if mapping:
            for slot in sequence:
                self[slot] = sequence[slot]
Add multiple elements to the fact.