def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def initialize(self, init_type = ema_init_type.KMEANS_INITIALIZATION):
        """!
        @brief Calculates initial parameters for EM algorithm: means and covariances using
                specified strategy.