def _keep_alive(x, memo):
    try:
        memo[id(memo)].append(x)
    except KeyError:
        # aha, this is the first one :-)
        memo[id(memo)]=[x]
Add a layer through a hub message
dataset/ETHPy150Open amrdraz/kodr/app/brython/www/src/Lib/copy.py/_keep_alive--crossover with--dataset/ETHPy150Open glue-viz/glue/glue/app/qt/tests/test_layer_tree_widget.py/TestLayerTree.add_layer