def fit_train(self, k_samples=100):
        """ Estimate the mean and std of the features from the training set
        Params:
            k_samples (int): Use this number of samples for estimation
        """
        k_samples = min(k_samples, len(self.train_audio_paths))
        samples = self.rng.sample(self.train_audio_paths, k_samples)
        feats = [self.featurize(s) for s in samples]
        feats = np.vstack(feats)
        self.feats_mean = np.mean(feats, axis=0)
        self.feats_std = np.std(feats, axis=0)
 Estimate the mean and std of the features from the training set
        Params:
            k_samples (int): Use this number of samples for estimation
        
data_generator.py