def set_cluster_fields(self, cluster_fields):
        ''' Tell the clusterizer the meaning of the field names.

        The cluster_fields parameter is a dict, e.g., {"new filed name": "standard field name"}.
        '''
        if not cluster_fields:
            cluster_fields_mapping_inverse = {}
            cluster_fields_mapping = {}
        else:
            # Create also the inverse dictionary for faster lookup
            cluster_fields_mapping_inverse = dict((k, v) for k, v in cluster_fields.items())
            cluster_fields_mapping = dict((v, k) for k, v in cluster_fields.items())

        for old_name, new_name in self._default_cluster_fields_mapping.items():
            if old_name not in cluster_fields_mapping:
                cluster_fields_mapping[old_name] = new_name
                cluster_fields_mapping_inverse[new_name] = old_name

        self._cluster_fields_mapping = cluster_fields_mapping
        self._cluster_fields_mapping_inverse = cluster_fields_mapping_inverse
Tell the clusterizer the meaning of the field names.

        The cluster_fields parameter is a dict, e.g., {"new filed name": "standard field name"}.