def _create_samples(self, configuration=EvaluationConfig(10, 1000)):

        #TODO: What is a reasonable limit to warn about a too small testset?
        if len(self.reference) < (configuration.num_samples *
                                  configuration.sample_size):
            _logger.warn("The test set is too small for this sample size")

        compound_list = sorted(self.reference.keys())
        self._samples[configuration] = [
            _sample(compound_list, configuration.sample_size, i) for i in
            range(configuration.num_samples)]
Create, in a stable manner, n testsets of size x as defined in
dataset/ETHPy150Open aalto-speech/morfessor/morfessor/evaluation.py/MorfessorEvaluation._create_samples