def forward(self):
        if self._index >= len(self._history) - 1:
            return None
        self._index += 1
        self._check_index()
        return self.current_item
Deletes the contents of the index.
dataset/ETHPy150Open kwikteam/phy/phy/cluster/manual/_history.py/History.forward--crossover with--dataset/ETHPy150Open hvandenb/splunk-elasticsearch/search-elasticsearch/bin/splunklib/client.py/Index.clean