@staticmethod
def _build_instances_dict(target_classes):
    """
        If there are target classes, we can build their dictionary now. Otherwise, all_classes_mode or
        shape_qualifiers_mode will fill the instances dict in future methods

        :param target_classes:
        :return:
        """
    result = {}
    if target_classes is not None:
        for a_class in target_classes:
            result[a_class.iri] = set()
    return result
