code: def ensure_self_loop(g):
      g = g.remove_self_loop()
      g = g.add_self_loop()
      return g
  
imports: import argparse
  import textwrap
  import tensorflow
  import tensorflow_addons
  from dgl.data import CiteseerGraphDataset, CoraGraphDataset, PubmedGraphDataset
  from dgl.nn.tensorflow.conv import SGConv
label_desc: Use image node_id 5 for calling the SGC obj's underlying member method code with example usage: obj.ensure_self_loop(g) and returns: g