<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _score_clusters(self, X, y=None):
 """ Determines the "scores" of the cluster, the metric that determines the size of the cluster visualized on the visualization. """

        stype = self.scoring.lower() # scoring method name

        if stype == "membership":
            return np.bincount(self.estimator.labels_)

        raise YellowbrickValueError("unknown scoring method '{}'".format(stype))