How to use the pycm.pycm_param.MAPPING_CLASS_NAME_ERROR function in pycm

def relabel(self, mapping):
        """
        This method rename ConfusionMatrix classes
        :param mapping: mapping dictionary
        :type mapping : dict
        :return: None
        """
        if not isinstance(mapping, dict):
            raise pycmMatrixError(MAPPING_FORMAT_ERROR)
        if self.classes != list(mapping.keys()):
            raise pycmMatrixError(MAPPING_CLASS_NAME_ERROR)
        for row in self.classes:
            temp_dict = {}
            temp_dict_normalized = {}
            for col in self.classes:
                temp_dict[mapping[col]] = self.table[row][col]
                temp_dict_normalized[mapping[col]
                                     ] = self.normalized_table[row][col]
            del self.table[row]
            self.table[mapping[row]] = temp_dict
            del self.normalized_table[row]
            self.normalized_table[mapping[row]] = temp_dict_normalized
        self.matrix = self.table
        self.normalized_matrix = self.normalized_table
        for param in self.class_stat.keys():
            temp_dict = {}
            for classname in self.classes: