code: def factory(cfg, src_db, dest_db):
          
          return obj_for_name(cfg[Transformation.__CFG_KEY_TRANSFORMATION_CLASS])(
              cfg[Transformation.CFG_KEY_TRANSFORMATION_CFG], src_db, dest_db)
docs: 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