def concat(self, streams):
        if self._execution_plan:
            self._execution_plan.append('concat', 'transform')

        return pd.concat(streams)
Each resource plugin is called to log free resource information.
dataset/ETHPy150Open Convertro/Hydro/src/hydro/transformers.py/Transformers.concat--crossover with--dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/compute/resources/__init__.py/ResourceHandler.report_free_resources