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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def plot_pauli_transfer_matrix(self, ax):
 """ Plot the elements of the Pauli transfer matrix. :param matplotlib.Axes ax: A matplotlib Axes object to plot into. """

        title = "Estimated process"
        ut.plot_pauli_transfer_matrix(self.r_est, ax, self.pauli_basis.labels, title)