<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _get_stddevs(self, C, distance, stddev_types):
 """ Returns the total standard deviation, which is a function of distance """

        stddevs = []
        for stddev_type in stddev_types:
            assert stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
            if stddev_type == const.StdDev.TOTAL:
                sigma = C["s1"] + (C["s2"] / (1.0 +
                                   ((distance / C["s3"]) ** 2.)))
                stddevs.append(sigma + np.zeros_like(distance))
        return stddevs