class_docstr: Network visualization "renderer" implementation to render a network with
  graphviz.
code: def render(self, graph):
      graph = nx.nx_agraph.to_agraph(graph)
      graph.layout()
  
      buffer = io.BytesIO()
      graph.draw(buffer, format="png", prog="dot")
      buffer.seek(0)
      img = mpimg.imread(buffer)
      plt.imshow(img)
      plt.show()
  
imports: import io
  import networkx
  import matplotlib.pyplot
  import matplotlib.image
label_desc: Use image node_id 1 for calling the GraphVizRenderer obj's underlying member method code with example usage: obj.render(graph) without return types