What is the proper way to reinitialize tf.Dataset with initializable iterator? I tried many ways and always results in memory leak. Should we use gc.collect or tf.reset_graph_default? How do I use tf.reset_graph_default if it always results in error “AssertionError: Do not use tf.reset_default_graph() to clear nested graphs. If you need a cleared graph, exit the nesting and create a new graph”?   I just want to change train dataset and continue training with new data