Instantiate Transformation
        :param cfg: transformation configuration
			"class": "na3x.transformation.transformer.Col2XTransformation", <Transformation class>
				"cfg": {
					"src.db.load": {
						"src": "sprint.backlog_links" <Collection(s) to be loaded>
					},
					"transform": {
						"func": "ext.transformers.gantt_links" <transformer function>
					},
					"dest.db.cleanup": {
						"target": "baseline.gantt_links" <Collection to be cleaned during transformation (usually the same as destination)>
					},
					"dest.db.save": {
						"dest": "baseline.gantt_links" <Destination collection>
					}
				}
        :param src_db: source db for transformation
        :param dest_db: destination db for transformation
        :return: Transformation instance

def factory(cfg, src_db, dest_db):
        """
        Instantiate Transformation
        :param cfg: transformation configuration
			"class": "na3x.transformation.transformer.Col2XTransformation", <Transformation class>
				"cfg": {
					"src.db.load": {
						"src": "sprint.backlog_links" <Collection(s) to be loaded>
					},
					"transform": {
						"func": "ext.transformers.gantt_links" <transformer function>
					},
					"dest.db.cleanup": {
						"target": "baseline.gantt_links" <Collection to be cleaned during transformation (usually the same as destination)>
					},
					"dest.db.save": {
						"dest": "baseline.gantt_links" <Destination collection>
					}
				}
        :param src_db: source db for transformation
        :param dest_db: destination db for transformation
        :return: Transformation instance
        """
        return obj_for_name(cfg[Transformation.__CFG_KEY_TRANSFORMATION_CLASS])(
            cfg[Transformation.CFG_KEY_TRANSFORMATION_CFG], src_db, dest_db)