title: Is there some easy way to assign positions to nx.Graph() nodes?
body: <p>Is there some way, to assign pos value to a nx.Graph(), so that it will be drawn using this value by default when nx.draw() is called?</p>
  <p>I want to store graphs in JSON format, and it would really help me if I would not have to store this information separately from the graph.</p>
  <p>For what I know it is possible to use add_node() with pos parameter, to add single node at some location, but can I assign positions to nodes already present in Graph?</p>