             density=density,
                                       thickness=thickness)
            res[name] = mat

        return res
    @classmethod
    def get_stix_ebins_transmission(cls, ebins=ins.ebins):
        pass
    @classmethod
    def create_material(cls,
                        name=None,
                        fractional_masses=None,
                        thickness=None,
                        density=None):
        &#34;&#34;&#34;
        Create a new material given the composition a