Creates a new model mapper from a dictionary mapping_matrix existing priors to new priors, keeping existing
        priors where no mapping is provided.

        Parameters
        ----------
        arguments: {Prior: Prior}
            A dictionary mapping_matrix priors to priors

        Returns
        -------
        model_mapper: ModelMapper
            A new model mapper with updated priors.

def mapper_from_partial_prior_arguments(self, arguments):
        """
        Creates a new model mapper from a dictionary mapping_matrix existing priors to new priors, keeping existing
        priors where no mapping is provided.

        Parameters
        ----------
        arguments: {Prior: Prior}
            A dictionary mapping_matrix priors to priors

        Returns
        -------
        model_mapper: ModelMapper
            A new model mapper with updated priors.
        """
        original_prior_dict = {prior: prior for prior in self.priors}
        return self.mapper_from_prior_arguments({**original_prior_dict, **arguments})