def get_pitch_class_transition_matrix(self, normalize=False,
                                          time_thresh=0.05):
        # Sum up all matrices from all instruments defaulting zeros matrix
        pc_trans_mat = sum(
            [i.get_pitch_class_transition_matrix(normalize, time_thresh)
             for i in self.instruments], np.zeros((12, 12)))

        # Normalize accordingly
        if normalize:
            pc_trans_mat /= (pc_trans_mat.sum() + (pc_trans_mat.sum() == 0))

        return pc_trans_mat
A pesistent request does not send 'Connection: close' header.
dataset/ETHPy150Open craffel/pretty-midi/pretty_midi/pretty_midi.py/PrettyMIDI.get_pitch_class_transition_matrix--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/web/test/test_newclient.py/RequestTests.test_sendSimplestPersistentRequest