Collates model results from all phases in the directory or some subset if filters are applied.

        Parameters
        ----------
        kwargs
            Filters, e.g. pipeline=pipeline1

        Returns
        -------
        model_results
            A string joining headers and results for all included phases.

def model_results(self, **kwargs) -> str:
        """
        Collates model results from all phases in the directory or some subset if filters are applied.

        Parameters
        ----------
        kwargs
            Filters, e.g. pipeline=pipeline1

        Returns
        -------
        model_results
            A string joining headers and results for all included phases.
        """
        return "\n\n".join("{}\n\n{}".format(phase.header, phase.model_results) for phase in
                           self.phases_with(**kwargs))