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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 set_irreps(self, q, is_little_cogroup=False, nac_q_direction=None, degeneracy_tolerance=1e-4):
 """Identify ir-reps of phonon modes. The design of this API is not very satisfactory and is expceted to be redesined in the next major versions once the use case of the API for ir-reps feature becomes clearer. """


        if self._dynamical_matrix is None:
            msg = ("Dynamical matrix has not yet built.")
            raise RuntimeError(msg)

        self._irreps = IrReps(
            self._dynamical_matrix,
            q,
            is_little_cogroup=is_little_cogroup,
            nac_q_direction=nac_q_direction,
            factor=self._factor,
            symprec=self._symprec,
            degeneracy_tolerance=degeneracy_tolerance,
            log_level=self._log_level)

        return self._irreps.run()