@staticmethod
def dilution_space_plateau(doseweight, molmass, doseenrichment,
    plateauenrichment, background):
    """Calculate a dilution space using the plateau method.
           :param doseweight: weight of the does in grams
           :param molmass: moleular mass of the dose in grams/mol
           :param doseenrichment: enrichment of the dose in ppm
           :param plateauenrichment: enrichment of the plateau urine measurement as a ratio
           :param background: enrichment of the background urine measurement as a ratio
           :return: dilution space calculated by the plateau method in mol
        """
    return doseweight / molmass * (doseenrichment - plateauenrichment) / (
        plateauenrichment - background)
