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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def reinforce(self, **kwargs):
 """ Reinforces the grid and calculates grid expansion costs. See :meth:`edisgo.flex_opt.reinforce_grid` for more information. """

        results = reinforce_grid(
            self, max_while_iterations=kwargs.get(
                'max_while_iterations', 10),
            copy_graph=kwargs.get('copy_graph', False),
            timesteps_pfa=kwargs.get('timesteps_pfa', None),
            combined_analysis=kwargs.get('combined_analysis', False))

        # add measure to Results object
        if not kwargs.get('copy_graph', False):
            self.network.results.measures = 'grid_expansion'

        return results