def _postcheck(self, network, feedin):
        """
        Raises an error if the curtailment of a generator exceeds the
        feed-in of that generator at any time step.

        Parameters
        -----------
        network : :class:`~.grid.network.Network`
        feedin : :pandas:`pandas.DataFrame<dataframe>`
            DataFrame with feed-in time series in kW. Columns of the dataframe
            are :class:`~.grid.components.GeneratorFluctuating`, index is
            time index.

        """
        curtailment = network.timeseries.curtailment
        gen_repr = [repr(_) for _ in curtailment.columns]
        feedin_repr = feedin.loc[:, gen_repr]
        curtailment_repr = curtailment
        curtailment_repr.columns = gen_repr
        if not ((feedin_repr - curtailment_repr) > -1e-1).all().all():
            message = 'Curtailment exceeds feed-in.'
            logging.error(message)
            raise TypeError(message)
Raises an error if the curtailment of a generator exceeds the
        feed-in of that generator at any time step.

        Parameters
        -----------
        network : :class:`~.grid.network.Network`
        feedin : :pandas:`pandas.DataFrame<dataframe>`
            DataFrame with feed-in time series in kW. Columns of the dataframe
            are :class:`~.grid.components.GeneratorFluctuating`, index is
            time index.